diff --git a/public/projects.ts b/public/projects.ts
index 8f29a77..6e17f6d 100644
Binary files a/public/projects.ts and b/public/projects.ts differ
diff --git a/src/http/worktrees.ts b/src/http/worktrees.ts
index c395f22..5445382 100644
--- a/src/http/worktrees.ts
+++ b/src/http/worktrees.ts
@@ -9,7 +9,12 @@ import fs from 'node:fs/promises'
 import path from 'node:path'
 import { execFile } from 'node:child_process'
 import { promisify } from 'node:util'
-import type { CreateWorktreeResult, WorktreeInfo } from '../types.js'
+import type {
+  CreateWorktreeResult,
+  PruneWorktreesResult,
+  RemoveWorktreeResult,
+  WorktreeInfo,
+} from '../types.js'
 
 const execFileAsync = promisify(execFile)
 
@@ -249,3 +254,137 @@ export async function createWorktree(
     return classifyWorktreeError(err)
   }
 }
+
+// ── W4: remove a worktree (validate → registered-check → contain → execFile) ────
+
+export interface RemoveWorktreeOptions {
+  readonly force?: boolean // git's own --force (required for a dirty tree)
+  readonly timeoutMs: number // cfg.worktreeTimeoutMs
+}
+
+/**
+ * Map a `git worktree remove` failure to a structured result with a SAFE message
+ * (never raw git stderr, SEC-M10). A dirty tree (git demands --force) → 409; an
+ * already-gone / not-a-working-tree race → 404; anything else → 500.
+ */
+function classifyRemoveError(err: unknown): RemoveWorktreeResult {
+  const s = extractStderr(err).toLowerCase()
+  if (
+    s.includes('contains modified or untracked files') ||
+    s.includes('use --force') ||
+    s.includes('use `--force`') ||
+    s.includes('is dirty')
+  ) {
+    return { ok: false, status: 409, error: 'Worktree has uncommitted changes — force required.' }
+  }
+  if (s.includes('not a working tree') || s.includes('is not a working tree')) {
+    return { ok: false, status: 404, error: 'That path is not a worktree of this repository.' }
+  }
+  return { ok: false, status: 500, error: 'Failed to remove the worktree.' }
+}
+
+/**
+ * Remove a git worktree — the destructive path. The security spine (never `rm`,
+ * always via git):
+ *   1. `isGitRepo(repoPath)` gate → 404.
+ *   2. non-empty string target → 400.
+ *   3. the target's REALPATH must equal the realpath of an entry git itself
+ *      reports in `worktree list` (canonical compare, defeats symlink tricks);
+ *      no match → 404. This registered-check IS the containment (M2-consistent):
+ *      an arbitrary FS path (e.g. /etc) can never match, so it is never touched.
+ *   4. the matched entry may not be the MAIN worktree → 400 (never delete the repo).
+ *   5. a LOCKED entry → 409 (unlock in a terminal first; never auto -f -f).
+ *   6. run `git worktree remove [--force] -- <git's own canonical path>` via
+ *      execFile (no shell, `--` terminates options), never the raw user string.
+ * Returns a structured RemoveWorktreeResult; never throws.
+ */
+export async function removeWorktree(
+  repoPath: string,
+  targetPath: string,
+  opts: RemoveWorktreeOptions,
+): Promise<RemoveWorktreeResult> {
+  if (!(await isGitRepo(repoPath))) {
+    return { ok: false, status: 404, error: 'Not a git repository.' }
+  }
+  if (typeof targetPath !== 'string' || targetPath.length === 0) {
+    return { ok: false, status: 400, error: 'Worktree path is required.' }
+  }
+
+  // Canonicalise the requested path and every registered worktree, then match on
+  // realpath — a symlink alias resolves to the same canonical target (M2).
+  const realTarget = await resolveRealPath(targetPath)
+  const worktrees = await listWorktrees(repoPath)
+  let match: WorktreeInfo | undefined
+  for (const wt of worktrees) {
+    if ((await resolveRealPath(wt.path)) === realTarget) {
+      match = wt
+      break
+    }
+  }
+  if (match === undefined) {
+    return { ok: false, status: 404, error: 'That path is not a worktree of this repository.' }
+  }
+  if (match.isMain) {
+    return { ok: false, status: 400, error: 'Cannot remove the main worktree.' }
+  }
+  if (match.locked === true) {
+    return { ok: false, status: 409, error: 'This worktree is locked; unlock it in a terminal first.' }
+  }
+
+  try {
+    const args = ['worktree', 'remove', ...(opts.force === true ? ['--force'] : []), '--', match.path]
+    await execFileAsync('git', args, {
+      cwd: repoPath,
+      timeout: opts.timeoutMs,
+      maxBuffer: WORKTREE_MAX_BUFFER,
+    })
+    return { ok: true, path: match.path }
+  } catch (err: unknown) {
+    return classifyRemoveError(err)
+  }
+}
+
+// ── W4: prune stale worktrees (folders that git can no longer find) ─────────────
+
+export interface PruneWorktreesOptions {
+  readonly timeoutMs: number // cfg.worktreeTimeoutMs
+}
+
+/**
+ * Parse `git worktree prune -v` output into best-effort human labels. git emits
+ * one `Removing <name>: <reason>` line per reclaimed entry (on stdout and/or
+ * stderr depending on version) — capture the label before the ':'. Pure.
+ */
+function parsePruneOutput(text: string): string[] {
+  const out: string[] = []
+  for (const raw of text.split('\n')) {
+    const line = raw.trim()
+    const m = /^Removing\s+(.+?):/.exec(line)
+    if (m !== null && m[1] !== undefined) out.push(m[1])
+  }
+  return out
+}
+
+/**
+ * Prune worktrees whose working directories are gone. `isGitRepo` gate (404),
+ * then `git worktree prune -v` via execFile (no shell). Idempotent — a clean repo
+ * yields `{ ok:true, pruned:[] }`. Returns a structured result; never throws.
+ */
+export async function pruneWorktrees(
+  repoPath: string,
+  opts: PruneWorktreesOptions,
+): Promise<PruneWorktreesResult> {
+  if (!(await isGitRepo(repoPath))) {
+    return { ok: false, status: 404, error: 'Not a git repository.' }
+  }
+  try {
+    const { stdout, stderr } = await execFileAsync('git', ['worktree', 'prune', '-v'], {
+      cwd: repoPath,
+      timeout: opts.timeoutMs,
+      maxBuffer: WORKTREE_MAX_BUFFER,
+    })
+    return { ok: true, pruned: parsePruneOutput(`${stdout}\n${stderr}`) }
+  } catch {
+    return { ok: false, status: 500, error: 'Failed to prune worktrees.' }
+  }
+}
diff --git a/src/server.ts b/src/server.ts
index 3f6ed34..19cf0d8 100644
--- a/src/server.ts
+++ b/src/server.ts
@@ -44,7 +44,7 @@ import { getGitLog } from './http/git-log.js'
 import { buildDigest, clampSince } from './http/digest.js'
 import { getPrStatus } from './http/gh.js'
 import { parseStatusLine } from './http/statusline.js'
-import { createWorktree } from './http/worktrees.js'
+import { createWorktree, removeWorktree, pruneWorktrees } from './http/worktrees.js'
 import { createSessionManager } from './session/manager.js'
 import { detachWs, writeInput, setClientDims } from './session/session.js'
 import { loadSubscriptionStore } from './push/subscription-store.js'
@@ -928,6 +928,58 @@ export function startServer(cfg: Config): { close(): Promise<void> } {
     res.status(result.status ?? 500).json({ error: result.error ?? 'Failed to create the worktree.' })
   })
 
+  // ── W4 remove a git worktree (destructive → Origin guard, same as create) ────
+  app.delete('/projects/worktree', express.json({ limit: '4kb' }), async (req, res) => {
+    if (!requireAllowedOrigin(req, res)) return
+    if (!cfg.worktreeEnabled) {
+      res.status(403).json({ error: 'Worktree management is disabled.' })
+      return
+    }
+    const body = (req.body ?? {}) as Record<string, unknown>
+    const repoPath = typeof body['path'] === 'string' ? body['path'] : undefined
+    const worktreePath = typeof body['worktreePath'] === 'string' ? body['worktreePath'] : undefined
+    const force = body['force'] === true
+    if (repoPath === undefined || worktreePath === undefined) {
+      res.status(400).json({ error: 'path and worktreePath are required' })
+      return
+    }
+    // Audit (destructive): who/what, sanitized + truncated (never raw control chars).
+    console.error(
+      `[server] worktree remove: path=${sanitizeForLog(repoPath)} worktree=${sanitizeForLog(worktreePath)} force=${force}`,
+    )
+    const result = await removeWorktree(repoPath, worktreePath, {
+      force,
+      timeoutMs: cfg.worktreeTimeoutMs,
+    })
+    if (result.ok) {
+      res.status(200).json({ ok: true, path: result.path })
+      return
+    }
+    res.status(result.status ?? 500).json({ error: result.error ?? 'Failed to remove the worktree.' })
+  })
+
+  // ── W4 prune stale worktrees (destructive → Origin guard) ────────────────────
+  app.post('/projects/worktree/prune', express.json({ limit: '4kb' }), async (req, res) => {
+    if (!requireAllowedOrigin(req, res)) return
+    if (!cfg.worktreeEnabled) {
+      res.status(403).json({ error: 'Worktree management is disabled.' })
+      return
+    }
+    const body = (req.body ?? {}) as Record<string, unknown>
+    const repoPath = typeof body['path'] === 'string' ? body['path'] : undefined
+    if (repoPath === undefined) {
+      res.status(400).json({ error: 'path is required' })
+      return
+    }
+    console.error(`[server] worktree prune: path=${sanitizeForLog(repoPath)}`)
+    const result = await pruneWorktrees(repoPath, { timeoutMs: cfg.worktreeTimeoutMs })
+    if (result.ok) {
+      res.status(200).json({ ok: true, pruned: result.pruned ?? [] })
+      return
+    }
+    res.status(result.status ?? 500).json({ error: result.error ?? 'Failed to prune worktrees.' })
+  })
+
   // ── GET /config/ui (review #4) — client-readable UI config (read-only) ────
   app.get('/config/ui', (_req, res) => {
     const uiConfig: UiConfig = {
diff --git a/src/types.ts b/src/types.ts
index f30f307..be39bd3 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -594,6 +594,26 @@ export interface CreateWorktreeResult {
   error?: string;
 }
 
+/** Result of DELETE /projects/worktree (W4 remove). `error` is a SAFE message
+ *  only (never raw git stderr, SEC-M10); `status` is the HTTP status to return.
+ *  `path` echoes git's own canonical worktree path that was removed. */
+export interface RemoveWorktreeResult {
+  ok: boolean;
+  path?: string;
+  status?: number;
+  error?: string;
+}
+
+/** Result of POST /projects/worktree/prune (W4). `pruned` lists best-effort
+ *  human labels of the stale worktrees git reclaimed (empty = nothing to prune,
+ *  idempotent). `error` is a SAFE message only (SEC-M10). */
+export interface PruneWorktreesResult {
+  ok: boolean;
+  pruned?: string[];
+  status?: number;
+  error?: string;
+}
+
 /* ── v0.6 Projects UI preferences (server-persisted, cross-device) ── */
 
 /** Cross-device UI preferences for the Projects launcher (impl: src/http/prefs-store.ts).
diff --git a/test/http/worktrees-remove.test.ts b/test/http/worktrees-remove.test.ts
new file mode 100644
index 0000000..1d71bf3
--- /dev/null
+++ b/test/http/worktrees-remove.test.ts
@@ -0,0 +1,186 @@
+/**
+ * test/http/worktrees-remove.test.ts — W4 worktree remove / prune (DESTRUCTIVE).
+ *
+ * Covers the two new exports of src/http/worktrees.ts:
+ *   - removeWorktree  (registered-check + main/locked reject + realpath match +
+ *                      dirty/force handling + safe error classification, SEC-M10)
+ *   - pruneWorktrees  (idempotent prune of stale worktrees)
+ *
+ * Everything runs against real temporary git repos with real linked worktrees
+ * (no network, no mocks) — mirrors worktrees-create.test.ts. Safety is the point:
+ * these tests assert git is never invoked against an arbitrary / main / escaping
+ * path, and that a dirty tree is refused without an explicit force.
+ */
+
+import { describe, it, expect, beforeAll } from 'vitest'
+import fs from 'node:fs/promises'
+import os from 'node:os'
+import path from 'node:path'
+import { execFile } from 'node:child_process'
+import { promisify } from 'node:util'
+import { createWorktree, removeWorktree, pruneWorktrees } from '../../src/http/worktrees.js'
+
+const execFileP = promisify(execFile)
+const TIMEOUT_MS = 10000
+
+let gitAvailable = false
+beforeAll(async () => {
+  try {
+    await execFileP('git', ['--version'])
+    gitAvailable = true
+  } catch {
+    gitAvailable = false
+  }
+})
+
+/** Create a temp git repo with one commit so `git worktree add` can run. */
+async function makeRepo(): Promise<string> {
+  const dir = await fs.mkdtemp(path.join(os.tmpdir(), 'wtrm-repo-'))
+  await execFileP('git', ['init', '-q', '-b', 'main'], { cwd: dir })
+  await execFileP('git', ['config', 'user.email', 't@t.local'], { cwd: dir })
+  await execFileP('git', ['config', 'user.name', 'tester'], { cwd: dir })
+  await execFileP('git', ['config', 'commit.gpgsign', 'false'], { cwd: dir })
+  await execFileP('git', ['commit', '-q', '--allow-empty', '-m', 'init'], { cwd: dir })
+  return dir
+}
+
+/** Create a repo + one linked worktree (via the shipped createWorktree). */
+async function makeRepoWithWorktree(branch = 'feature'): Promise<{ repo: string; wt: string }> {
+  const repo = await makeRepo()
+  const res = await createWorktree(repo, branch, { timeoutMs: TIMEOUT_MS })
+  expect(res.ok).toBe(true)
+  return { repo, wt: res.path as string }
+}
+
+async function worktreeList(repo: string): Promise<string> {
+  const { stdout } = await execFileP('git', ['worktree', 'list'], { cwd: repo })
+  return stdout
+}
+
+// ── removeWorktree ──────────────────────────────────────────────────────────────
+
+describe('removeWorktree', () => {
+  it('returns 404 for a non-git directory', async () => {
+    const plain = await fs.mkdtemp(path.join(os.tmpdir(), 'wtrm-plain-'))
+    const res = await removeWorktree(plain, plain, { timeoutMs: TIMEOUT_MS })
+    expect(res).toMatchObject({ ok: false, status: 404 })
+  })
+
+  it('returns 400 for an empty target path', async () => {
+    if (!gitAvailable) return
+    const repo = await makeRepo()
+    const res = await removeWorktree(repo, '', { timeoutMs: TIMEOUT_MS })
+    expect(res).toMatchObject({ ok: false, status: 400 })
+  })
+
+  it('returns 404 for a path that is not a registered worktree (never rm arbitrary paths)', async () => {
+    if (!gitAvailable) return
+    const repo = await makeRepo()
+    const stranger = await fs.mkdtemp(path.join(os.tmpdir(), 'wtrm-stranger-'))
+    const res = await removeWorktree(repo, stranger, { timeoutMs: TIMEOUT_MS })
+    expect(res).toMatchObject({ ok: false, status: 404 })
+    // The stranger dir was never touched by git.
+    await expect(fs.stat(stranger)).resolves.toBeDefined()
+  })
+
+  it('refuses to remove the MAIN worktree (the repo itself) with 400', async () => {
+    if (!gitAvailable) return
+    const repo = await makeRepo()
+    const res = await removeWorktree(repo, repo, { timeoutMs: TIMEOUT_MS })
+    expect(res).toMatchObject({ ok: false, status: 400 })
+    expect(res.error).toMatch(/main/i)
+    // The repo still exists and is still a git repo.
+    await expect(fs.stat(path.join(repo, '.git'))).resolves.toBeDefined()
+  })
+
+  it('removes a clean linked worktree and returns ok', async () => {
+    if (!gitAvailable) return
+    const { repo, wt } = await makeRepoWithWorktree()
+    expect(await worktreeList(repo)).toContain(wt)
+    const res = await removeWorktree(repo, wt, { timeoutMs: TIMEOUT_MS })
+    expect(res.ok).toBe(true)
+    expect(res.path).toBeDefined()
+    expect(await worktreeList(repo)).not.toContain(wt)
+  })
+
+  it('refuses a dirty worktree without force (409), then removes it with force', async () => {
+    if (!gitAvailable) return
+    const { repo, wt } = await makeRepoWithWorktree()
+    // Untracked file → git refuses `worktree remove` without --force.
+    await fs.writeFile(path.join(wt, 'scratch.txt'), 'wip\n', 'utf8')
+
+    const refused = await removeWorktree(repo, wt, { timeoutMs: TIMEOUT_MS })
+    expect(refused).toMatchObject({ ok: false, status: 409 })
+    // Still present — no data was lost.
+    expect(await worktreeList(repo)).toContain(wt)
+
+    const forced = await removeWorktree(repo, wt, { force: true, timeoutMs: TIMEOUT_MS })
+    expect(forced.ok).toBe(true)
+    expect(await worktreeList(repo)).not.toContain(wt)
+  })
+
+  it('never leaks raw git stderr in the dirty-tree error (SEC-M10)', async () => {
+    if (!gitAvailable) return
+    const { repo, wt } = await makeRepoWithWorktree()
+    await fs.writeFile(path.join(wt, 'scratch.txt'), 'wip\n', 'utf8')
+    const res = await removeWorktree(repo, wt, { timeoutMs: TIMEOUT_MS })
+    expect(res.ok).toBe(false)
+    expect(res.error).toBeDefined()
+    expect(res.error).not.toContain('fatal:')
+    expect(res.error).not.toContain('error:')
+    expect(res.error).not.toContain(wt) // no path leak
+  })
+
+  it('refuses a locked worktree with 409 (unlock first; never auto -f -f)', async () => {
+    if (!gitAvailable) return
+    const { repo, wt } = await makeRepoWithWorktree()
+    await execFileP('git', ['worktree', 'lock', wt], { cwd: repo })
+    const res = await removeWorktree(repo, wt, { force: true, timeoutMs: TIMEOUT_MS })
+    expect(res).toMatchObject({ ok: false, status: 409 })
+    expect(res.error).toMatch(/lock/i)
+    expect(await worktreeList(repo)).toContain(wt)
+  })
+
+  it('matches a symlink alias via realpath and removes git\'s canonical path (M2)', async () => {
+    if (!gitAvailable) return
+    const { repo, wt } = await makeRepoWithWorktree()
+    const aliasParent = await fs.mkdtemp(path.join(os.tmpdir(), 'wtrm-alias-'))
+    const alias = path.join(aliasParent, 'link-to-wt')
+    await fs.symlink(wt, alias)
+    // Passing the symlink still resolves to the same registered worktree.
+    const res = await removeWorktree(repo, alias, { timeoutMs: TIMEOUT_MS })
+    expect(res.ok).toBe(true)
+    expect(await worktreeList(repo)).not.toContain(wt)
+  })
+})
+
+// ── pruneWorktrees ──────────────────────────────────────────────────────────────
+
+describe('pruneWorktrees', () => {
+  it('returns 404 for a non-git directory', async () => {
+    const plain = await fs.mkdtemp(path.join(os.tmpdir(), 'wtrm-pruneplain-'))
+    const res = await pruneWorktrees(plain, { timeoutMs: TIMEOUT_MS })
+    expect(res).toMatchObject({ ok: false, status: 404 })
+  })
+
+  it('prunes a worktree whose folder was deleted out-of-band', async () => {
+    if (!gitAvailable) return
+    const { repo, wt } = await makeRepoWithWorktree()
+    // Simulate a user rm -rf'ing the worktree dir behind git's back.
+    await fs.rm(wt, { recursive: true, force: true })
+    const res = await pruneWorktrees(repo, { timeoutMs: TIMEOUT_MS })
+    expect(res.ok).toBe(true)
+    expect(Array.isArray(res.pruned)).toBe(true)
+    expect((res.pruned as string[]).length).toBeGreaterThanOrEqual(1)
+    // git no longer lists the stale worktree.
+    expect(await worktreeList(repo)).not.toContain(wt)
+  })
+
+  it('is idempotent — a clean repo prunes nothing', async () => {
+    if (!gitAvailable) return
+    const repo = await makeRepo()
+    const res = await pruneWorktrees(repo, { timeoutMs: TIMEOUT_MS })
+    expect(res).toMatchObject({ ok: true })
+    expect(res.pruned).toEqual([])
+  })
+})
diff --git a/test/integration/worktree.test.ts b/test/integration/worktree.test.ts
index 3d58bbb..755974f 100644
--- a/test/integration/worktree.test.ts
+++ b/test/integration/worktree.test.ts
@@ -190,6 +190,176 @@ describe('POST /projects/worktree (B3)', () => {
   })
 })
 
+// ── DELETE /projects/worktree (W4 remove) ─────────────────────────────────────────
+
+/** Create a worktree via the POST route; returns its git path. */
+async function createWorktreeViaRoute(
+  port: number,
+  origin: string,
+  repo: string,
+  branch: string,
+): Promise<string> {
+  const res = await fetch(`http://127.0.0.1:${port}/projects/worktree`, {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json', Origin: origin },
+    body: JSON.stringify({ path: repo, branch }),
+  })
+  expect(res.status).toBe(200)
+  const body = (await res.json()) as { ok: boolean; path?: string }
+  expect(body.ok).toBe(true)
+  return body.path as string
+}
+
+describe('DELETE /projects/worktree (W4)', () => {
+  it('rejects a foreign Origin with 403 (SEC-C3)', async () => {
+    const { port } = await spawnServer()
+    const res = await fetch(`http://127.0.0.1:${port}/projects/worktree`, {
+      method: 'DELETE',
+      headers: { 'Content-Type': 'application/json', Origin: 'http://evil.example' },
+      body: JSON.stringify({ path: '/tmp/x', worktreePath: '/tmp/x/wt' }),
+    })
+    expect(res.status).toBe(403)
+  })
+
+  it('rejects a missing Origin with 403', async () => {
+    const { port } = await spawnServer()
+    const res = await fetch(`http://127.0.0.1:${port}/projects/worktree`, {
+      method: 'DELETE',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ path: '/tmp/x', worktreePath: '/tmp/x/wt' }),
+    })
+    expect(res.status).toBe(403)
+  })
+
+  it('returns 403 when WORKTREE_ENABLED=0', async () => {
+    const { port, origin } = await spawnServer({ WORKTREE_ENABLED: '0' })
+    const res = await fetch(`http://127.0.0.1:${port}/projects/worktree`, {
+      method: 'DELETE',
+      headers: { 'Content-Type': 'application/json', Origin: origin },
+      body: JSON.stringify({ path: '/tmp/x', worktreePath: '/tmp/x/wt' }),
+    })
+    expect(res.status).toBe(403)
+  })
+
+  it('returns 400 when worktreePath is missing', async () => {
+    const { port, origin } = await spawnServer()
+    const res = await fetch(`http://127.0.0.1:${port}/projects/worktree`, {
+      method: 'DELETE',
+      headers: { 'Content-Type': 'application/json', Origin: origin },
+      body: JSON.stringify({ path: '/tmp/x' }),
+    })
+    expect(res.status).toBe(400)
+  })
+
+  itGit('refuses to remove the main worktree with 400', async () => {
+    const repo = await makeRealRepo()
+    const { port, origin } = await spawnServer()
+    const res = await fetch(`http://127.0.0.1:${port}/projects/worktree`, {
+      method: 'DELETE',
+      headers: { 'Content-Type': 'application/json', Origin: origin },
+      body: JSON.stringify({ path: repo, worktreePath: repo }),
+    })
+    expect(res.status).toBe(400)
+  })
+
+  itGit('removes a clean linked worktree and returns ok (200)', async () => {
+    const repo = await makeRealRepo()
+    const root = await fs.mkdtemp(path.join(os.tmpdir(), 'webterm-rmroot-'))
+    tmpDirs.push(root)
+    const { port, origin } = await spawnServer({ WORKTREE_ROOT: root })
+    const wt = await createWorktreeViaRoute(port, origin, repo, 'to-remove')
+    expect(execFileSync('git', ['worktree', 'list'], { cwd: repo }).toString()).toContain(wt)
+
+    const res = await fetch(`http://127.0.0.1:${port}/projects/worktree`, {
+      method: 'DELETE',
+      headers: { 'Content-Type': 'application/json', Origin: origin },
+      body: JSON.stringify({ path: repo, worktreePath: wt }),
+    })
+    expect(res.status).toBe(200)
+    const body = (await res.json()) as { ok: boolean; path?: string }
+    expect(body.ok).toBe(true)
+    expect(execFileSync('git', ['worktree', 'list'], { cwd: repo }).toString()).not.toContain(wt)
+  })
+
+  itGit('refuses a dirty worktree (409), then removes it with force (200)', async () => {
+    const repo = await makeRealRepo()
+    const root = await fs.mkdtemp(path.join(os.tmpdir(), 'webterm-dirtyroot-'))
+    tmpDirs.push(root)
+    const { port, origin } = await spawnServer({ WORKTREE_ROOT: root })
+    const wt = await createWorktreeViaRoute(port, origin, repo, 'dirty-one')
+    await fs.writeFile(path.join(wt, 'scratch.txt'), 'wip\n', 'utf8')
+
+    const refused = await fetch(`http://127.0.0.1:${port}/projects/worktree`, {
+      method: 'DELETE',
+      headers: { 'Content-Type': 'application/json', Origin: origin },
+      body: JSON.stringify({ path: repo, worktreePath: wt }),
+    })
+    expect(refused.status).toBe(409)
+
+    const forced = await fetch(`http://127.0.0.1:${port}/projects/worktree`, {
+      method: 'DELETE',
+      headers: { 'Content-Type': 'application/json', Origin: origin },
+      body: JSON.stringify({ path: repo, worktreePath: wt, force: true }),
+    })
+    expect(forced.status).toBe(200)
+    expect(execFileSync('git', ['worktree', 'list'], { cwd: repo }).toString()).not.toContain(wt)
+  })
+})
+
+// ── POST /projects/worktree/prune (W4) ────────────────────────────────────────────
+
+describe('POST /projects/worktree/prune (W4)', () => {
+  it('rejects a foreign Origin with 403', async () => {
+    const { port } = await spawnServer()
+    const res = await fetch(`http://127.0.0.1:${port}/projects/worktree/prune`, {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json', Origin: 'http://evil.example' },
+      body: JSON.stringify({ path: '/tmp/x' }),
+    })
+    expect(res.status).toBe(403)
+  })
+
+  it('returns 403 when WORKTREE_ENABLED=0', async () => {
+    const { port, origin } = await spawnServer({ WORKTREE_ENABLED: '0' })
+    const res = await fetch(`http://127.0.0.1:${port}/projects/worktree/prune`, {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json', Origin: origin },
+      body: JSON.stringify({ path: '/tmp/x' }),
+    })
+    expect(res.status).toBe(403)
+  })
+
+  it('returns 400 when path is missing', async () => {
+    const { port, origin } = await spawnServer()
+    const res = await fetch(`http://127.0.0.1:${port}/projects/worktree/prune`, {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json', Origin: origin },
+      body: JSON.stringify({}),
+    })
+    expect(res.status).toBe(400)
+  })
+
+  itGit('prunes a worktree whose folder was deleted out-of-band (200)', async () => {
+    const repo = await makeRealRepo()
+    const root = await fs.mkdtemp(path.join(os.tmpdir(), 'webterm-pruneroot-'))
+    tmpDirs.push(root)
+    const { port, origin } = await spawnServer({ WORKTREE_ROOT: root })
+    const wt = await createWorktreeViaRoute(port, origin, repo, 'stale-one')
+    await fs.rm(wt, { recursive: true, force: true })
+
+    const res = await fetch(`http://127.0.0.1:${port}/projects/worktree/prune`, {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json', Origin: origin },
+      body: JSON.stringify({ path: repo }),
+    })
+    expect(res.status).toBe(200)
+    const body = (await res.json()) as { ok: boolean; pruned: string[] }
+    expect(body.ok).toBe(true)
+    expect(Array.isArray(body.pruned)).toBe(true)
+    expect(execFileSync('git', ['worktree', 'list'], { cwd: repo }).toString()).not.toContain(wt)
+  })
+})
+
 // ── GET /projects/diff ───────────────────────────────────────────────────────────
 
 describe('GET /projects/diff (B1)', () => {
diff --git a/test/worktree-form.test.ts b/test/worktree-form.test.ts
index 5615201..c521793 100644
--- a/test/worktree-form.test.ts
+++ b/test/worktree-form.test.ts
@@ -11,7 +11,7 @@
  */
 
 import { describe, it, expect, vi, beforeEach } from 'vitest'
-import type { ProjectDetail } from '../src/types.js'
+import type { ProjectDetail, WorktreeInfo } from '../src/types.js'
 
 // ── Stub @xterm/xterm (transitively via preview-grid.ts) ──────────────────────
 class FakeTerminal {
@@ -41,8 +41,14 @@ const mockMountPrChip = vi.fn(() => mockPrChipHandle)
 vi.mock('../public/gh-chip.js', () => ({ mountPrChip: mockMountPrChip }))
 
 // ── Import AFTER mocks ─────────────────────────────────────────────────────────
-const { validateBranchNameClient, renderNewWorktreeForm, renderProjectDetail } =
-  await import('../public/projects.js')
+const {
+  validateBranchNameClient,
+  renderNewWorktreeForm,
+  renderProjectDetail,
+  makeWorktreeRow,
+  confirmAndRemoveWorktree,
+  confirmAndPruneWorktrees,
+} = await import('../public/projects.js')
 
 /* ── Helpers ───────────────────────────────────────────────────────────────── */
 
@@ -579,3 +585,226 @@ describe('renderProjectDetail — A4 Activity section', () => {
     expect(mockDiffHandle.destroy).toHaveBeenCalled()
   })
 })
+
+/* ── W4: makeWorktreeRow remove button ─────────────────────────────────────── */
+
+function wt(overrides: Partial<WorktreeInfo> = {}): WorktreeInfo {
+  return { path: '/repo/wt/feat', branch: 'feat', isMain: false, isCurrent: false, ...overrides }
+}
+
+describe('makeWorktreeRow — W4 remove button', () => {
+  const actions = { onRemove: vi.fn() }
+
+  it('adds a remove button for a non-main, non-locked worktree when actions are given', () => {
+    const row = makeWorktreeRow(wt(), actions)
+    expect(row.querySelector('.proj-wt-remove')).not.toBeNull()
+  })
+
+  it('omits the remove button when no actions are given (read-only row)', () => {
+    const row = makeWorktreeRow(wt())
+    expect(row.querySelector('.proj-wt-remove')).toBeNull()
+  })
+
+  it('never offers a remove button for the main worktree', () => {
+    const row = makeWorktreeRow(wt({ isMain: true, branch: 'main' }), actions)
+    expect(row.querySelector('.proj-wt-remove')).toBeNull()
+    expect(row.textContent).toContain('main')
+  })
+
+  it('never offers a remove button for a locked worktree (keeps the locked tag)', () => {
+    const row = makeWorktreeRow(wt({ locked: true }), actions)
+    expect(row.querySelector('.proj-wt-remove')).toBeNull()
+    expect(row.textContent).toContain('locked')
+  })
+
+  it('still offers a remove button for a prunable worktree', () => {
+    const row = makeWorktreeRow(wt({ prunable: true }), actions)
+    expect(row.querySelector('.proj-wt-remove')).not.toBeNull()
+  })
+
+  it('clicking the remove button calls onRemove with the worktree', () => {
+    const onRemove = vi.fn()
+    const w = wt()
+    const row = makeWorktreeRow(w, { onRemove })
+    ;(row.querySelector('.proj-wt-remove') as HTMLButtonElement).click()
+    expect(onRemove).toHaveBeenCalledWith(w)
+  })
+})
+
+/* ── W4: renderProjectDetail prune button + remove wiring ──────────────────── */
+
+describe('renderProjectDetail — W4 prune + remove wiring', () => {
+  const mainWt: WorktreeInfo = { path: '/repo', branch: 'main', isMain: true, isCurrent: true }
+  const featWt: WorktreeInfo = { path: '/repo/wt/feat', branch: 'feat', isMain: false, isCurrent: false }
+  const staleWt: WorktreeInfo = {
+    path: '/repo/wt/gone', branch: 'gone', isMain: false, isCurrent: false, prunable: true,
+  }
+
+  it('shows a "Prune stale worktrees" button when a worktree is prunable and a callback is wired', () => {
+    const root = renderProjectDetail(
+      makeDetail({ worktrees: [mainWt, staleWt] }),
+      makeHooks(),
+      { ...makeCbs(), onPruneWorktrees: vi.fn() },
+    )
+    expect(root.querySelector('.proj-wt-prune')).not.toBeNull()
+  })
+
+  it('hides the prune button when no worktree is prunable', () => {
+    const root = renderProjectDetail(
+      makeDetail({ worktrees: [mainWt, featWt] }),
+      makeHooks(),
+      { ...makeCbs(), onPruneWorktrees: vi.fn() },
+    )
+    expect(root.querySelector('.proj-wt-prune')).toBeNull()
+  })
+
+  it('hides the prune button when no prune callback is wired (pre-W4 callers)', () => {
+    const root = renderProjectDetail(makeDetail({ worktrees: [mainWt, staleWt] }), makeHooks(), makeCbs())
+    expect(root.querySelector('.proj-wt-prune')).toBeNull()
+  })
+
+  it('threads onRemoveWorktree so clicking a row remove button passes the worktree path', () => {
+    const onRemoveWorktree = vi.fn()
+    const root = renderProjectDetail(
+      makeDetail({ worktrees: [mainWt, featWt] }),
+      makeHooks(),
+      { ...makeCbs(), onRemoveWorktree },
+    )
+    const btn = root.querySelector('.proj-wt-remove') as HTMLButtonElement
+    expect(btn).not.toBeNull()
+    btn.click()
+    expect(onRemoveWorktree).toHaveBeenCalledWith('/repo/wt/feat')
+  })
+
+  it('clicking prune invokes onPruneWorktrees', () => {
+    const onPruneWorktrees = vi.fn()
+    const root = renderProjectDetail(
+      makeDetail({ worktrees: [mainWt, staleWt] }),
+      makeHooks(),
+      { ...makeCbs(), onPruneWorktrees },
+    )
+    ;(root.querySelector('.proj-wt-prune') as HTMLButtonElement).click()
+    expect(onPruneWorktrees).toHaveBeenCalled()
+  })
+})
+
+/* ── W4: confirmAndRemoveWorktree / confirmAndPruneWorktrees ───────────────── */
+
+describe('confirmAndRemoveWorktree — confirm → (force) → refresh flow', () => {
+  it('confirms, DELETEs with force:false, and returns "removed" on success', async () => {
+    vi.spyOn(window, 'confirm').mockReturnValue(true)
+    const mockFetch = vi.fn().mockResolvedValue({ ok: true, status: 200, json: async () => ({ ok: true }) })
+    vi.stubGlobal('fetch', mockFetch)
+
+    const outcome = await confirmAndRemoveWorktree('/repo', '/repo/wt/feat', vi.fn())
+    expect(outcome).toBe('removed')
+    expect(mockFetch).toHaveBeenCalledWith(
+      '/projects/worktree',
+      expect.objectContaining({
+        method: 'DELETE',
+        body: JSON.stringify({ path: '/repo', worktreePath: '/repo/wt/feat', force: false }),
+      }),
+    )
+  })
+
+  it('on a 409 dirty refusal, asks a SECOND confirm then retries with force:true', async () => {
+    vi.spyOn(window, 'confirm').mockReturnValue(true)
+    const mockFetch = vi
+      .fn()
+      .mockResolvedValueOnce({ ok: false, status: 409, json: async () => ({ ok: false, error: 'dirty' }) })
+      .mockResolvedValueOnce({ ok: true, status: 200, json: async () => ({ ok: true }) })
+    vi.stubGlobal('fetch', mockFetch)
+
+    const outcome = await confirmAndRemoveWorktree('/repo', '/repo/wt/feat', vi.fn())
+    expect(outcome).toBe('removed')
+    expect(mockFetch).toHaveBeenCalledTimes(2)
+    // Second call carries force:true.
+    expect(mockFetch.mock.calls[1]?.[1]).toMatchObject({
+      body: JSON.stringify({ path: '/repo', worktreePath: '/repo/wt/feat', force: true }),
+    })
+  })
+
+  it('does NOT fetch when the user cancels the first confirm (no accidental delete)', async () => {
+    vi.spyOn(window, 'confirm').mockReturnValue(false)
+    const mockFetch = vi.fn()
+    vi.stubGlobal('fetch', mockFetch)
+
+    const outcome = await confirmAndRemoveWorktree('/repo', '/repo/wt/feat', vi.fn())
+    expect(outcome).toBe('cancelled')
+    expect(mockFetch).not.toHaveBeenCalled()
+  })
+
+  it('does NOT force-delete when the user cancels the second (force) confirm', async () => {
+    vi.spyOn(window, 'confirm').mockReturnValueOnce(true).mockReturnValueOnce(false)
+    const mockFetch = vi
+      .fn()
+      .mockResolvedValueOnce({ ok: false, status: 409, json: async () => ({ ok: false, error: 'dirty' }) })
+    vi.stubGlobal('fetch', mockFetch)
+
+    const outcome = await confirmAndRemoveWorktree('/repo', '/repo/wt/feat', vi.fn())
+    expect(outcome).toBe('cancelled')
+    expect(mockFetch).toHaveBeenCalledTimes(1) // only the non-force attempt
+  })
+
+  it('reports a safe error via the onError callback and renders it via textContent (SEC-L3/H6)', async () => {
+    vi.spyOn(window, 'confirm').mockReturnValue(true)
+    const mockFetch = vi
+      .fn()
+      .mockResolvedValue({ ok: false, status: 500, json: async () => ({ ok: false, error: 'boom' }) })
+    vi.stubGlobal('fetch', mockFetch)
+
+    const errEl = document.createElement('div')
+    const onError = (msg: string): void => { errEl.textContent = msg }
+    const outcome = await confirmAndRemoveWorktree('/repo', '/repo/wt/feat', onError)
+
+    expect(outcome).toBe('error')
+    expect(errEl.textContent).toBe('boom')
+    expect(errEl.querySelector('script')).toBeNull() // textContent, never innerHTML
+  })
+
+  it('reports a safe error on network failure (never throws)', async () => {
+    vi.spyOn(window, 'confirm').mockReturnValue(true)
+    vi.stubGlobal('fetch', vi.fn().mockRejectedValue(new Error('offline')))
+    const onError = vi.fn()
+    const outcome = await confirmAndRemoveWorktree('/repo', '/repo/wt/feat', onError)
+    expect(outcome).toBe('error')
+    expect(onError).toHaveBeenCalled()
+  })
+})
+
+describe('confirmAndPruneWorktrees', () => {
+  it('confirms, POSTs to the prune route, and returns "pruned" on success', async () => {
+    vi.spyOn(window, 'confirm').mockReturnValue(true)
+    const mockFetch = vi
+      .fn()
+      .mockResolvedValue({ ok: true, status: 200, json: async () => ({ ok: true, pruned: [] }) })
+    vi.stubGlobal('fetch', mockFetch)
+
+    const outcome = await confirmAndPruneWorktrees('/repo', vi.fn())
+    expect(outcome).toBe('pruned')
+    expect(mockFetch).toHaveBeenCalledWith(
+      '/projects/worktree/prune',
+      expect.objectContaining({ method: 'POST', body: JSON.stringify({ path: '/repo' }) }),
+    )
+  })
+
+  it('does NOT fetch when the user cancels', async () => {
+    vi.spyOn(window, 'confirm').mockReturnValue(false)
+    const mockFetch = vi.fn()
+    vi.stubGlobal('fetch', mockFetch)
+    const outcome = await confirmAndPruneWorktrees('/repo', vi.fn())
+    expect(outcome).toBe('cancelled')
+    expect(mockFetch).not.toHaveBeenCalled()
+  })
+
+  it('reports a safe error via onError on failure', async () => {
+    vi.spyOn(window, 'confirm').mockReturnValue(true)
+    vi.stubGlobal('fetch', vi.fn().mockResolvedValue({
+      ok: false, status: 500, json: async () => ({ ok: false, error: 'nope' }),
+    }))
+    const onError = vi.fn()
+    const outcome = await confirmAndPruneWorktrees('/repo', onError)
+    expect(outcome).toBe('error')
+    expect(onError).toHaveBeenCalledWith('nope')
+  })
+})