[codex] Harden recovery issue handling (#4600)

## Thinking Path

> - Paperclip orchestrates AI agents for zero-human companies
> - The control plane must recover stranded agent work without creating
new operational loops
> - Stranded recovery issues can themselves fail, and exposing raw retry
errors in comments can leak sensitive adapter details
> - New local companies also should not force a hire-approval gate
unless operators enable that policy
> - This pull request hardens recovery issue handling, redacts retry
failure details in issue copy, preserves `maxConcurrentRuns: 1`, and
flips new-hire approval to an opt-in default
> - The benefit is safer automatic recovery and smoother default company
setup without hidden migration conflicts

## What Changed

- Added migration `0071_default_hire_approval_off` and updated company
schema/import/export/docs so hire approvals default off and serialize
only when enabled.
- Added migration `0072_large_sandman` with a partial unique index
preventing duplicate active stranded recovery issues for the same source
issue.
- Blocked failed `stranded_issue_recovery` issues in place instead of
creating nested recovery issues.
- Redacted latest retry failure details from recovery issue comments
while still linking reviewers to run evidence.
- Allowed `maxConcurrentRuns: 1` to be honored by heartbeat concurrency
normalization.
- Added focused regression coverage for recovery recursion, redaction,
migration ordering, and concurrency behavior.

## Verification

- `pnpm --filter @paperclipai/db run check:migrations`
- `pnpm exec vitest run --project @paperclipai/server
server/src/__tests__/recovery-classifiers.test.ts`
- `pnpm exec vitest run --project @paperclipai/server
server/src/__tests__/company-portability.test.ts --pool=forks
--poolOptions.forks.isolate=true`
- `pnpm exec vitest run --project @paperclipai/server
server/src/__tests__/agent-permissions-routes.test.ts --pool=forks
--poolOptions.forks.isolate=true`
- `pnpm --filter @paperclipai/server typecheck`
- `pnpm exec vitest run --project @paperclipai/server
server/src/__tests__/heartbeat-process-recovery.test.ts --pool=forks
--poolOptions.forks.isolate=true` exits 0, but this host skipped the
embedded Postgres tests with the existing init guard.
- `pnpm exec vitest run --project @paperclipai/server
server/src/__tests__/heartbeat-dependency-scheduling.test.ts
--pool=forks --poolOptions.forks.isolate=true` exits 0, but this host
skipped the embedded Postgres tests with the existing init guard.

## Risks

- Migration risk is low but this PR intentionally owns both new
migrations to avoid separate PR migration-journal conflicts.
- Recovery comments now require operators to inspect linked run evidence
for details instead of reading raw errors inline.
- The hire approval default changes behavior for newly created/imported
companies only; existing persisted company settings are not changed
except by the SQL default for future rows.

> 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 coding agent, tool-enabled terminal/GitHub
workflow, reasoning mode active. Context window not exposed in this
environment.

## 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
- [x] 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/start/core-concepts.md

@@ -57,9 +57,9 @@ The CEO is the primary delegator. When you set company goals, the CEO:
 1. Creates a strategy and submits it for your approval
 2. Breaks approved goals into tasks
 3. Assigns tasks to agents based on their role and capabilities
-4. Hires new agents when needed (subject to your approval)
+4. Hires new agents when needed, with hire approvals available when you enable them
 
-You don't need to manually assign every task — set the goals and let the CEO organize the work. You approve key decisions (strategy, hiring) and monitor progress. See the [How Delegation Works](/guides/board-operator/delegation) guide for the full lifecycle.
+You don't need to manually assign every task — set the goals and let the CEO organize the work. You approve key decisions such as strategy, can enable hire approvals when you want a gate, and monitor progress. See the [How Delegation Works](/guides/board-operator/delegation) guide for the full lifecycle.
 
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