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/terminal-session.ts

@@ -54,6 +54,8 @@ export interface TerminalSessionOpts {
   onClaudeStatus?: (status: ClaudeStatus, detail?: string) => void
   /** Optional: spawn a NEW session in this directory ("new tab here", M6). */
   cwd?: string
+  /** Optional: type this once the new session's shell is ready (O2 resume). */
+  initialInput?: string
 }
 
 export class TerminalSession {
@@ -69,6 +71,8 @@ export class TerminalSession {
   private readonly onStatus: ((status: SessionStatus) => void) | undefined
   private readonly onClaudeStatus: ((status: ClaudeStatus, detail?: string) => void) | undefined
   private readonly spawnCwd: string | undefined
+  private readonly initialInput: string | undefined
+  private initialSent = false
   private statusValue: SessionStatus = 'connecting'
   private claudeStatusValue: ClaudeStatus = 'unknown'
   private cwdValue: string | null = null
@@ -94,6 +98,7 @@ export class TerminalSession {
     this.onStatus = opts.onStatus
     this.onClaudeStatus = opts.onClaudeStatus
     this.spawnCwd = opts.cwd
+    this.initialInput = opts.initialInput
 
     this.el = document.createElement('div')
     this.el.className = 'term-pane'
@@ -238,6 +243,12 @@ export class TerminalSession {
         this.onSessionId(msg.sessionId)
         const dims = this.safefit()
         if (dims !== null) this.sendResize(dims.cols, dims.rows)
+        // O2: once the shell is up, type the resume command (only on first attach).
+        if (this.initialInput !== undefined && !this.initialSent) {
+          this.initialSent = true
+          const cmd = this.initialInput
+          setTimeout(() => this.send(cmd), 700)
+        }
         break
       }
       case 'output': {