feat(bottle): random-suffix identity + cli.py resume <identity>

Replaces the cwd-hash identity with a random 5-char base36 suffix
per launch, so two simultaneous `start <agent>` invocations against
the same cwd no longer collide on container names. Each launch is
its own bottle.

State carries metadata: every prepare step writes
~/.claude-bottle/state/<identity>/metadata.json with the
(agent_name, cwd, copy_cwd, started_at) the bottle was launched
with. The new `cli.py resume <identity>` reads this metadata and
re-launches a bottle pinned to the same identity — picking up the
per-bottle Dockerfile (from a prior capability-block apply) and
the transcript snapshot under the same state dir.

- bottle_state.py: bottle_identity(agent_name) drops the cwd param
  and gains a random suffix; BottleMetadata dataclass +
  read/write/metadata_path helpers.
- BottleSpec gains an optional identity field — resume sets it to
  pin the identity; start leaves it empty so prepare mints fresh.
- prepare.py: writes metadata at launch time; uses spec.identity if
  provided (resume) else bottle_identity(agent_name) (fresh start).
- start.py: extracted _launch_bottle from cmd_start so resume can
  share the launch core; prints `./cli.py resume <identity>` hint
  at session end.
- cli/resume.py (new): reads metadata, reconstructs BottleSpec
  with the recorded identity + cwd, delegates to _launch_bottle.
  Errors clearly when no state exists for the given identity.
- cli/__init__.py: registers `resume` in COMMANDS + usage.
- dashboard.py: capability-block approval status line now appends
  the `resume <identity>` hint so the operator can copy-paste the
  rebuild command without leaving the TUI.

Closes the rebuild loop in PRD 0016: agent calls capability-block →
operator approves → bottle torn down with state preserved → status
line shows resume command → operator runs it → replacement bottle
boots with the new Dockerfile and prior transcript.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

claude_bottle/cli/dashboard.py

@@ -112,6 +112,16 @@ def discover_pipelock_slugs() -> list[str]:
     return _discover_sidecar_slugs("claude-bottle-pipelock-")
 
 
+def _approval_status(qp: QueuedProposal, verb: str) -> str:
+    """Status-line text after a successful approval. For capability-
+    block, append the `resume <identity>` hint so the operator can
+    bring the rebuilt bottle back up with one copy-paste."""
+    base = f"{verb} {qp.proposal.tool} for [{qp.proposal.bottle_slug}]"
+    if qp.proposal.tool == TOOL_CAPABILITY_BLOCK:
+        return f"{base}; resume: ./cli.py resume {qp.proposal.bottle_slug}"
+    return base
+
+
 def discover_pending() -> list[QueuedProposal]:
     """Walk ~/.claude-bottle/queue/* and collect pending proposals
     from every bottle's queue. Sorted by arrival time across the
@@ -371,7 +381,7 @@ def _main_loop(stdscr: "curses._CursesWindow") -> None:
         elif key == ord("a"):
             try:
                 approve(qp)
-                status_line = f"approved {qp.proposal.tool} for [{qp.proposal.bottle_slug}]"
+                status_line = _approval_status(qp, "approved")
             except ApplyError as e:
                 status_line = f"apply failed: {e}"
         elif key == ord("m"):
@@ -381,7 +391,7 @@ def _main_loop(stdscr: "curses._CursesWindow") -> None:
             else:
                 try:
                     approve(qp, final_file=edited, notes="operator modified before approving")
-                    status_line = f"modified+approved {qp.proposal.tool} for [{qp.proposal.bottle_slug}]"
+                    status_line = _approval_status(qp, "modified+approved")
                 except ApplyError as e:
                     status_line = f"apply failed: {e}"
         elif key == ord("r"):