feat(v0.3): O2 — resume past Claude sessions

- src/http/history.ts: listSessions() reads ~/.claude/projects/*/*.jsonl
  (mtime-sorted, top 50), parseSessionMeta() extracts cwd + first user prompt
  (pure, 4 unit tests); GET /sessions
- terminal-session: opts.initialInput (typed ~700ms after the shell is ready)
- tabs.newTabForResume(cwd,id): new tab in the project dir running
  'claude --resume <id>'
- public/history.ts: 🕘 panel listing sessions (project · time · preview) with
  Resume buttons
- Verified: /sessions returns 44 real sessions; panel lists project/time/preview.
  216 tests green.

public/tabs.ts

@@ -151,7 +151,12 @@ export class TabApp {
 
   /* ── tab lifecycle ───────────────────────────────────────────── */
 
-  private addEntry(sessionId: string | null, customTitle: string | null, cwd?: string): TabEntry {
+  private addEntry(
+    sessionId: string | null,
+    customTitle: string | null,
+    cwd?: string,
+    initialInput?: string,
+  ): TabEntry {
     const entry: TabEntry = {
       session: null as unknown as TerminalSession,
       customTitle,
@@ -162,6 +167,7 @@ export class TabApp {
     entry.session = new TerminalSession({
       sessionId,
       ...(cwd !== undefined ? { cwd } : {}),
+      ...(initialInput !== undefined ? { initialInput } : {}),
       onSessionId: () => this.persist(),
       // onActivity only fires for hidden (inactive) panes (see TerminalSession).
       onActivity: () => {
@@ -198,6 +204,14 @@ export class TabApp {
     this.activate(this.tabs.length - 1)
   }
 
+  /** O2: open a new tab in `cwd` and run `claude --resume <id>`. */
+  newTabForResume(cwd: string, sessionId: string): void {
+    this.addEntry(null, null, cwd || undefined, `claude --resume ${sessionId}`)
+    this.persist()
+    this.rebuild()
+    this.activate(this.tabs.length - 1)
+  }
+
   activate(i: number): void {
     if (i < 0 || i >= this.tabs.length) return
     this.maybeAskNotify() // first switch is a user gesture — request notif permission