Guard assigned backlog liveness (#5428)

## Thinking Path

> - Paperclip orchestrates AI agents for zero-human companies
> - The issue graph and liveness recovery system decide whether assigned
work is executable or parked
> - Assigned issues created without an explicit status could silently
land in backlog, making parents look blocked with no productive wake
path
> - The server, shared validators, recovery analysis, and UI all need to
agree on that execution semantic
> - This pull request makes assigned issue creation default to `todo`,
flags assigned backlog blockers, and surfaces the state in the board
> - The benefit is that parked assigned work becomes intentional and
visible instead of creating silent liveness stalls

## What Changed

- Adds contract tests for assigned issue creation defaults.
- Defaults assigned issue creation to `todo` when status is omitted
while preserving explicit `backlog` parking.
- Exposes `resolveCreateIssueStatusDefault` through shared validators.
- Teaches liveness/blocker attention paths to distinguish assigned
backlog blockers.
- Adds UI notices, row/header badges, and issue detail safeguards for
assigned backlog blockers.
- Adds Storybook fixtures and execution-semantics documentation for the
assigned-backlog behavior.

## Verification

- `pnpm run preflight:workspace-links && pnpm exec vitest run
packages/shared/src/validators/issue.test.ts
server/src/__tests__/issue-assigned-backlog-contract-routes.test.ts
server/src/__tests__/issue-blocker-attention.test.ts
server/src/__tests__/issue-liveness.test.ts
server/src/__tests__/heartbeat-issue-liveness-escalation.test.ts
ui/src/components/IssueAssignedBacklogNotice.test.tsx
ui/src/components/IssueRow.test.tsx` — 50 passed, 23 skipped.
- Skipped tests were embedded Postgres suites on this host with the repo
skip message: `Postgres init script exited with code null. Please check
the logs for extra info. The data directory might already exist.`
- Pairwise merge check against the issue-controls PR branch completed
without conflicts via `git merge --no-commit --no-ff` in a temporary
worktree.
- Screenshots for assigned-backlog UI states:
[light](docs/pr-screenshots/pr-5428/assigned-backlog-light.png),
[dark](docs/pr-screenshots/pr-5428/assigned-backlog-dark.png).
- Follow-up checks: `pnpm --filter /ui typecheck`; `pnpm --filter
/mcp-server build`; `pnpm --filter /mcp-server test`; `pnpm exec vitest
run packages/shared/src/validators/issue.test.ts`; focused UI component
tests.
- Remote PR checks on head `6300b3c`: policy, verify, serialized server
shards 1/4-4/4, Canary Dry Run, e2e, Greptile Review, and Snyk all
passed.

## Risks

- Medium: changes status defaulting for assigned issue creation when the
caller omits status. Explicit `backlog` remains supported, and
server/shared tests cover both paths.
- Medium: liveness classification changes can affect blocker attention
labels; focused service and UI tests cover the new assigned-backlog
state.

> 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 coding agent, GPT-5 model family (`gpt-5`), tool-enabled
Paperclip heartbeat environment. Context window and internal reasoning
mode are not exposed by the runtime.

## 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>

server/src/services/issues.ts

@@ -1309,6 +1309,9 @@ async function listIssueBlockerAttentionMap(
     if (explicitWaitingIssueIds.has(node.id)) {
       return { covered: true, stalled: false, sampleBlockerIdentifier: nodeSample, sampleStalledBlockerIdentifier: null };
     }
+    if (node.assigneeUserId && node.status !== "cancelled") {
+      return { covered: true, stalled: false, sampleBlockerIdentifier: nodeSample, sampleStalledBlockerIdentifier: null };
+    }
     if (node.status === "in_review") {
       const hasWaitingPath = activeIssueIds.has(node.id) || Boolean(node.assigneeUserId);
       if (hasWaitingPath) {
@@ -1322,6 +1325,9 @@ async function listIssueBlockerAttentionMap(
     if (node.status === "cancelled") {
       return { covered: false, stalled: false, sampleBlockerIdentifier: nodeSample, sampleStalledBlockerIdentifier: null };
     }
+    if (node.status === "backlog" && node.assigneeAgentId) {
+      return { covered: false, stalled: false, sampleBlockerIdentifier: nodeSample, sampleStalledBlockerIdentifier: null };
+    }
 
     const downstream = (edgesByIssueId.get(node.id) ?? []).filter((edge) => nodesById.get(edge.blockerIssueId)?.status !== "done");
     if (downstream.length > 0) {

server/src/services/recovery/issue-graph-liveness.ts

@@ -4,6 +4,7 @@ export type IssueLivenessSeverity = "warning" | "critical";
 
 export type IssueLivenessState =
   | "blocked_by_unassigned_issue"
+  | "blocked_by_assigned_backlog_issue"
   | "blocked_by_uninvokable_assignee"
   | "blocked_by_cancelled_issue"
   | "invalid_review_participant"
@@ -498,6 +499,21 @@ export function classifyIssueGraphLiveness(input: IssueGraphLivenessInput): Issu
       return reviewFinding(source, blocker, dependencyPath);
     }
 
+    if (blocker.status === "backlog" && blocker.assigneeAgentId) {
+      return finding({
+        issue: source,
+        state: "blocked_by_assigned_backlog_issue",
+        reason: `${issueLabel(source)} is blocked by assigned backlog issue ${issueLabel(blocker)} with no wake, active run, human owner, interaction, approval, monitor, or recovery issue owning the next action.`,
+        dependencyPath,
+        recoveryIssue: blocker,
+        recommendedOwnerCandidateAgentIds: ownerCandidates.map((candidate) => candidate.agentId),
+        recommendedOwnerCandidates: ownerCandidates,
+        recommendedAction:
+          `Review ${issueLabel(blocker)} and either move it to todo so the assignee wakes, assign a human owner or interaction if it is intentionally parked, or remove it from ${issueLabel(source)}'s blockers if it is no longer required.`,
+        blockerIssueId: blocker.id,
+      });
+    }
+
     if (!blocker.assigneeAgentId && !blocker.assigneeUserId) {
       return finding({
         issue: source,

server/src/services/recovery/service.ts

@@ -2089,19 +2089,41 @@ export function recoveryService(db: Db, deps: { enqueueWakeup: RecoveryWakeup })
           companyId: issues.companyId,
           id: issues.id,
           status: issues.status,
+          originKind: issues.originKind,
           originId: issues.originId,
         })
         .from(issues)
         .where(
           and(
             isNull(issues.hiddenAt),
-            eq(issues.originKind, STRANDED_ISSUE_RECOVERY_ORIGIN_KIND),
+            inArray(issues.originKind, [
+              STRANDED_ISSUE_RECOVERY_ORIGIN_KIND,
+              RECOVERY_ORIGIN_KINDS.issueGraphLivenessEscalation,
+            ]),
             notInArray(issues.status, ["done", "cancelled"]),
           ),
         ),
     ]);
 
     const openRecoveryIssues = recoveryIssueRows.flatMap((row) => {
+      if (row.originKind === RECOVERY_ORIGIN_KINDS.issueGraphLivenessEscalation) {
+        const parsed = parseIssueGraphLivenessIncidentKey(row.originId);
+        if (!parsed || parsed.companyId !== row.companyId) return [];
+        if (parsed.state !== "blocked_by_assigned_backlog_issue") return [];
+        return [
+          {
+            companyId: row.companyId,
+            issueId: parsed.issueId,
+            status: row.status,
+          },
+          {
+            companyId: row.companyId,
+            issueId: parsed.leafIssueId,
+            status: row.status,
+          },
+        ];
+      }
+
       const issueId = readNonEmptyString(row.originId);
       if (!issueId) return [];
       return [{