[codex] Add structured issue-thread interactions (#4244)

## Thinking Path

> - Paperclip orchestrates AI agents for zero-human companies.
> - Operators supervise that work through issues, comments, approvals,
and the board UI.
> - Some agent proposals need structured board/user decisions, not
hidden markdown conventions or heavyweight governed approvals.
> - Issue-thread interactions already provide a natural thread-native
surface for proposed tasks and questions.
> - This pull request extends that surface with request confirmations,
richer interaction cards, and agent/plugin/MCP helpers.
> - The benefit is that plan approvals and yes/no decisions become
explicit, auditable, and resumable without losing the single-issue
workflow.

## What Changed

- Added persisted issue-thread interactions for suggested tasks,
structured questions, and request confirmations.
- Added board UI cards for interaction review, selection, question
answers, and accept/reject confirmation flows.
- Added MCP and plugin SDK helpers for creating interaction cards from
agents/plugins.
- Updated agent wake instructions, onboarding assets, Paperclip skill
docs, and public docs to prefer structured confirmations for
issue-scoped decisions.
- Rebased the branch onto `public-gh/master` and renumbered branch
migrations to `0063` and `0064`; the idempotency migration uses `ADD
COLUMN IF NOT EXISTS` for old branch users.

## Verification

- `git diff --check public-gh/master..HEAD`
- `pnpm exec vitest run packages/adapter-utils/src/server-utils.test.ts
packages/mcp-server/src/tools.test.ts
packages/shared/src/issue-thread-interactions.test.ts
ui/src/lib/issue-thread-interactions.test.ts
ui/src/lib/issue-chat-messages.test.ts
ui/src/components/IssueThreadInteractionCard.test.tsx
ui/src/components/IssueChatThread.test.tsx
server/src/__tests__/issue-thread-interaction-routes.test.ts
server/src/__tests__/issue-thread-interactions-service.test.ts
server/src/services/issue-thread-interactions.test.ts` -> 9 files / 79
tests passed
- `pnpm -r typecheck` -> passed, including `packages/db` migration
numbering check

## Risks

- Medium: this adds a new issue-thread interaction model across
db/shared/server/ui/plugin surfaces.
- Migration risk is reduced by placing this branch after current master
migrations (`0063`, `0064`) and making the idempotency column add
idempotent for users who applied the old branch numbering.
- UI interaction behavior is covered by component tests, but this PR
does not include browser screenshots.

> For core feature work, check [`ROADMAP.md`](ROADMAP.md) first and
discuss it in `#dev` before opening the PR. Feature PRs that overlap
with planned core work may need to be redirected — check the roadmap
first. See `CONTRIBUTING.md`.

## Model Used

- OpenAI Codex, GPT-5-class coding agent runtime. Exact model ID and
context window are not exposed in this Paperclip run; tool use and local
shell/code execution were enabled.

## Checklist

- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [ ] If this change affects the UI, I have included before/after
screenshots
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [x] I will address all Greptile and reviewer comments before
requesting merge

---------

Co-authored-by: Paperclip <noreply@paperclip.ing>

docs/guides/agent-developer/heartbeat-protocol.md

@@ -70,6 +70,8 @@ Use your tools and capabilities to complete the task. If the issue is actionable
 
 Leave durable progress in comments, documents, or work products, and include the next action before exiting. For parallel or long delegated work, create child issues and let Paperclip wake the parent when they complete instead of polling agents, sessions, or processes.
 
+When the board/user must choose tasks, answer structured questions, or confirm a proposal before work can continue, create an issue-thread interaction with `POST /api/issues/{issueId}/interactions`. Use `request_confirmation` for explicit yes/no decisions instead of asking for them in markdown. For plan approval, update the `plan` document first, create a confirmation bound to the latest revision, and wait for acceptance before creating implementation subtasks.
+
 ### Step 8: Update Status
 
 Always include the run ID header on state changes:
@@ -107,6 +109,7 @@ Always set `parentId` and `goalId` on subtasks.
 - **Start actionable work** in the same heartbeat; planning-only exits are for planning tasks
 - **Leave a clear next action** in durable issue context
 - **Use child issues instead of polling** for long or parallel delegated work
+- **Use `request_confirmation`** for issue-scoped yes/no decisions and plan approval cards
 - **Always set parentId** on subtasks
 - **Never cancel cross-team tasks** — reassign to your manager
 - **Escalate when stuck** — use your chain of command