[The Framework] Resume a finished run by sending it a message (auto-resume)

[suleimansh]

Part of #719. From dogfooding #715: after a run ends (Stop, or it finishes), the chat composer disappears (it only renders on a live run). We want to keep chatting - your next message continues the same conversation.

Decision (user, over a Resume button): auto-resume on send. No extra button - the finished-run composer stays, and sending a message spins a fresh run whose opening prompt resumes the captured session.

Mechanism (the plumbing already mostly exists):

• We capture the agent session id per run (RunMeta.sessionId / the session-update event; visible in the log as session <id>).
• Today DriverPromptOptions.resume only resumes for chat turns WITHIN a live run, because the driver seeds lastSessionId from its own first turn. To revive a finished run, the OPENING prompt of a NEW run must resume a GIVEN id.
• Add a --resume-session <id> path: seed ClaudeCodeSession.lastSessionId at start so the opening prompt(firstPrompt, {resume:true}) resumes. Thread through runPrompt/runFramework -> daemon startRun -> sendStart.

UI:

• Render the composer on RunReplay (finished runs), not just RunLive.
• On send, start a new run with the message as the prompt + the finished run's captured session id. Subtle hint like "Run ended - your next message continues it."
• Reuse the navigate-on-start / followLive pattern (feat(framework-dashboard): jump to the run's live output on Start #705) so the new run's live output is shown.

Note the drain-only fallback flagged on #715 is exactly this: a series of runs stitched by the shared session id.