fix(projects): drop parent folders; attribute sessions to the deepest project

The projects panel listed bare parent folders (~, ~/Documents) as projects and
a single session lit up every ancestor project's 'Active now'. dropParentFolders
filters non-git entries that merely contain other listed projects; assignSessions
attributes each live session to the DEEPEST containing project (detail page keeps
prefix matching). +3 tests; projects 29/29, tsc clean. Frontend unchanged.

src/http/projects.ts

@@ -259,6 +259,18 @@ function dedupByPath(projects: readonly ProjectInfo[]): ProjectInfo[] {
   return out
 }
 
+/**
+ * Drop bare parent folders: a non-git entry (from session history — e.g. the
+ * home dir or ~/Documents, where a session once ran) that merely contains
+ * other discovered projects is not a project itself; listing it would also
+ * double-claim its children's sessions in the UI.
+ */
+function dropParentFolders(projects: readonly ProjectInfo[]): ProjectInfo[] {
+  return projects.filter(
+    (p) => p.isGit || !projects.some((q) => q.path !== p.path && belongsTo(q.path, p.path)),
+  )
+}
+
 async function runDiscovery(cfg: Config): Promise<ProjectInfo[]> {
   const repoPaths = await scanRepos(cfg.projectRoots, cfg.projectScanDepth)
   const repos = await mapWithConcurrency(repoPaths, GIT_CONCURRENCY, async (repoPath) => {
@@ -267,7 +279,7 @@ async function runDiscovery(cfg: Config): Promise<ProjectInfo[]> {
     return makeProject({ path: repoPath, isGit: true, branch, dirty })
   })
   const merged = await mergeHistory(repos)
-  return dedupByPath(merged)
+  return dropParentFolders(dedupByPath(merged))
 }
 
 /**
@@ -333,6 +345,29 @@ function matchSessions(projectPath: string, live: readonly LiveSessionInfo[]): P
   return live.filter((s) => belongsTo(s.cwd, projectPath)).map(toSessionRef)
 }
 
+/**
+ * Attribute each live session to the DEEPEST project containing its cwd.
+ * Plain prefix matching would also light up every ancestor project (e.g. a
+ * nested repo's session showing as active on the containing repo too).
+ */
+function assignSessions(
+  projects: readonly ProjectInfo[],
+  live: readonly LiveSessionInfo[],
+): Map<string, ProjectSessionRef[]> {
+  const byPath = new Map<string, ProjectSessionRef[]>()
+  for (const s of live) {
+    let deepest: string | undefined
+    for (const p of projects) {
+      if (!belongsTo(s.cwd, p.path)) continue
+      if (deepest === undefined || p.path.length > deepest.length) deepest = p.path
+    }
+    if (deepest === undefined) continue
+    const refs = byPath.get(deepest) ?? []
+    byPath.set(deepest, [...refs, toSessionRef(s)])
+  }
+  return byPath
+}
+
 function sortProjects(projects: readonly ProjectInfo[]): ProjectInfo[] {
   return [...projects].sort((a, b) => {
     if (a.lastActiveMs !== b.lastActiveMs) {
@@ -354,9 +389,10 @@ export async function buildProjects(
   liveSessions: readonly LiveSessionInfo[],
 ): Promise<ProjectInfo[]> {
   const base = await discoverProjects(cfg)
+  const sessionsByPath = assignSessions(base, liveSessions)
   const withSessions = base.map((p) => ({
     ...p,
-    sessions: matchSessions(p.path, liveSessions),
+    sessions: sessionsByPath.get(p.path) ?? [],
   }))
   return sortProjects(withSessions).slice(0, MAX_PROJECTS)
 }