Cockpit: implement chat UX, follow-up drafting, and guarded action forms

[smota]

Background & Problem Statement

Epic: #119

Cockpit has a guarded action endpoint and intent helpers, but no complete user-facing chat/steering UX or follow-up drafting workflow.

Proposed Solution

Build UI forms and chat-like lane for typed intents: ask status, add clarification, request checkpoint, request human review, draft follow-up, post handover, and start next phase.

Requirements

• Chat/status answers cite durable evidence.
• Guarded action forms require preview and confirmation.
• Follow-up draft flow turns review findings or replay gaps into issue drafts.
• Forbidden actions show policy reason.
• Material steering posts GitHub evidence or issue section update.
• Remote write actions require authz, CSRF, audit, and configured enablement.

Acceptance criteria

• User can draft follow-up issue from finding/gap.
• User can post clarification/handover through guarded form.
• Forbidden action attempts are blocked in UI and API.
• Action result links to GitHub comment/issue.
• Audit event visible/downloadable to authorized admin.

Test plan

• Component/E2E tests for guarded forms.
• API policy tests.
• Accessibility smoke for forms.

Workflow classification

High-assurance remote write UX. Requires security review.

[github-actions]

Integrated into development by PR #133: #133

Merge commit: 823d2e784f61e11645d2902e35401134fe0b1bdc
Release/promotion to main is tracked separately.