feat(ultraplan-local): pre-compact-flush refreshes session-state.local.json [skip-docs]

Extends the PreCompact hook with a sibling block that refreshes
.session-state.local.json's updated_at when status is in_progress or
partial. Per-project: runs after the existing progress.json mutation,
inside the same loop iteration.

Design:
- Only refreshes existing state files; creation is the writer's job
  (ultraexecute Phase 8 / 2.55 / 4 + future helper command).
- Monotonic guard: only updated_at is touched. project, status,
  next_session_brief_path, next_session_label remain owned by the writer.
- Skips status in {completed, failed, stopped} — the latter two are
  operator-action-required and silently bumping updated_at would mask
  alert state.
- Always exit 0; never blocks compaction.

[skip-docs] rationale: README + CLAUDE.md updates land in Step 11.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

plugins/ultraplan-local/hooks/scripts/pre-compact-flush.mjs

@@ -6,6 +6,10 @@
 //          Direct fix for the documented P0 in
 //          docs/ultraexecute-v2-observations-from-config-audit-v4.md.
 //
+//          v3.3.0: also refreshes sibling .session-state.local.json
+//          (Handover 7) so /ultracontinue can detect a resumable session
+//          even after a compaction event mid-run.
+//
 // Behavior:
 //   1. Locate {cwd}/.claude/projects/* / progress.json (any nested project)
 //   2. Read progress.json + sibling plan.md
@@ -13,12 +17,17 @@
 //   4. For each commit, match against plan steps' commit_message_pattern
 //   5. If derived current_step > stored current_step → write fresh checkpoint
 //      atomically (tmp + rename), monotonic only (current_step never decreases).
-//   6. Always exit 0 — NEVER blocks compaction.
+//   6. Refresh sibling .session-state.local.json if present and status is
+//      resumable (in_progress | partial) — bumps updated_at only. Never
+//      creates the state file; creation is the writer's job at session-end.
+//      Skips if status is completed/failed/stopped (non-resumable or terminal).
+//   7. Always exit 0 — NEVER blocks compaction.
 //
 // v3.3.0:
 //   - atomicWrite extracted to lib/util/atomic-write.mjs for reuse
 //   - File reformatted (removed pre-existing leading-whitespace syntax error
 //     that silently broke the hook since v3.1.0; PreCompact swallowed it)
+//   - Added Handover 7 sibling-state refresh
 
 import { readFileSync, existsSync, readdirSync, statSync } from 'node:fs';
 import { join, dirname } from 'node:path';
@@ -104,6 +113,25 @@ function repoRootOf(dir) {
   } catch { return null; }
 }
 
+// Resumable statuses for .session-state.local.json. `completed` is terminal;
+// `failed`/`stopped` are operator-action-required and should NOT be silently
+// refreshed by a background hook (would mask the alert). We only bump
+// updated_at for in_progress | partial — the active-work statuses.
+const SESSION_STATE_REFRESHABLE = new Set(['in_progress', 'partial']);
+
+function refreshSessionState(projDir) {
+  const statePath = join(projDir, '.session-state.local.json');
+  if (!existsSync(statePath)) return false;
+  const state = readJson(statePath);
+  if (!state || typeof state !== 'object') return false;
+  if (!SESSION_STATE_REFRESHABLE.has(state.status)) return false;
+  // Monotonic guard: only mutate updated_at. Never touch status, project,
+  // next_session_*. The writer (Phase 8 / helper) owns those fields.
+  state.updated_at = new Date().toISOString();
+  atomicWriteJson(statePath, state);
+  return true;
+}
+
 let stdinPayload = '';
 try { stdinPayload = readFileSync(0, 'utf-8'); } catch { /* fine */ }
 
@@ -142,7 +170,15 @@ for (const { projDir, progPath, planPath } of progressFiles) {
       };
     }
     atomicWriteJson(progPath, progress);
-    process.stderr.write(`[ultraplan-local] pre-compact flush: ${progPath} → current_step=${derivedStep}\n`);
+    process.stderr.write(`[ultraplan-local] pre-compact flush: ${progPath} -> current_step=${derivedStep}\n`);
+    mutationsMade++;
+  }
+
+  // Sibling .session-state.local.json refresh (Handover 7). Independent of
+  // progress.json mutation — the state file may exist for a session that
+  // hasn't advanced step yet, and we still want updated_at to track liveness.
+  if (refreshSessionState(projDir)) {
+    process.stderr.write(`[ultraplan-local] pre-compact refresh: ${projDir}/.session-state.local.json\n`);
     mutationsMade++;
   }
 }