diff --git a/plugins/ultraplan-local/commands/ultracontinue-local.md b/plugins/ultraplan-local/commands/ultracontinue-local.md
index 7562c94..ee53e3d 100644
--- a/plugins/ultraplan-local/commands/ultracontinue-local.md
+++ b/plugins/ultraplan-local/commands/ultracontinue-local.md
@@ -46,9 +46,11 @@ Phase 1. Do NOT print the usage block on empty args.
 /ultracontinue — Resume the next session in a multi-session ultraplan project.
 
 Usage:
-  /ultracontinue                  # auto-discover state file under cwd
-  /ultracontinue <project-dir>    # explicit project directory
-  /ultracontinue --help           # this message
+  /ultracontinue                                       # auto-discover state file under cwd
+  /ultracontinue <project-dir>                         # explicit project directory
+  /ultracontinue --cleanup <project-dir>               # dry-run: list stale files
+  /ultracontinue --cleanup --confirm <project-dir>     # actually delete (requires status: completed)
+  /ultracontinue --help                                # this message
 
 Reads .claude/projects/<project>/.session-state.local.json (per-project,
 gitignored). On a valid resumable state, prints a 3-line summary and begins
@@ -72,6 +74,52 @@ Typical flow:
   /ultracontinue                   # reads session-state, runs next session
 ```
 
+## Phase 0.5 — Cleanup mode dispatch
+
+After `parseArgs` has resolved `$ARGUMENTS`, check the parsed `flags`
+object directly (NOT a string contains-check on raw `$ARGUMENTS` — that
+substring pattern was the root cause of Bug 1).
+
+If `flags['--cleanup'] === true`, switch into the terminal cleanup
+flow and do NOT proceed to Phase 1 or any later phase.
+
+**Required positional:** an explicit `<project-dir>` (`positional[0]`).
+There is no "clean all" mode — accidental wholesale deletion would be
+irreversible. If `positional[0]` is missing, empty, or starts with `-`,
+print this usage block to stderr and exit non-zero:
+
+```
+Error: /ultracontinue-local --cleanup requires <project-dir>.
+Usage:
+  /ultracontinue-local --cleanup <project-dir>            # dry-run: list stale files
+  /ultracontinue-local --cleanup --confirm <project-dir>  # actually delete (status: completed)
+```
+
+**Compute mode from parsed flags:**
+
+```
+dryRun  = (flags['--confirm'] !== true)
+confirm = (flags['--confirm'] === true)
+```
+
+**Invoke cleanup inline.** Emit the concrete project-dir path as a literal
+token in the Bash command — never a template placeholder — same
+anti-substitution rule as Phase 2:
+
+```
+node --input-type=module -e "import {cleanupProject} from './lib/util/cleanup.mjs'; const [, dir, mode] = process.argv; const r = cleanupProject(dir, {dryRun: mode !== 'confirm', confirm: mode === 'confirm'}); console.log(JSON.stringify(r, null, 2)); process.exit(r.valid ? 0 : 1)" '<RESOLVED-PROJECT-DIR>' '<MODE>'
+```
+
+Substitute `<RESOLVED-PROJECT-DIR>` with the literal `positional[0]`
+value you have in your working context, and `<MODE>` with either the
+literal string `dryrun` or the literal string `confirm` based on the
+booleans above. The validator emits a `{valid, errors, warnings, parsed}`
+JSON record. Print it to stdout. Exit with the validator's exit code.
+
+**Cleanup is a terminal mode.** It must not fall through to Phase 1/2/3/4.
+Operators who want to resume after cleanup must invoke `/ultracontinue`
+again without `--cleanup`.
+
 ## Phase 1 — Resolve project directory
 
 The parsed `positional[0]` from Phase 0 is the explicit project-dir argument,
diff --git a/plugins/ultraplan-local/tests/commands/ultracontinue.test.mjs b/plugins/ultraplan-local/tests/commands/ultracontinue.test.mjs
index 130974a..ba3c53f 100644
--- a/plugins/ultraplan-local/tests/commands/ultracontinue.test.mjs
+++ b/plugins/ultraplan-local/tests/commands/ultracontinue.test.mjs
@@ -267,3 +267,85 @@ test('ultracontinue Bug 2 — Phase 2 contains no {state-file-path} or any {curl
     'Phase 2 must document the deterministic Read tool flow',
   );
 });
+
+// ---------------------------------------------------------------
+// Step 10 — Bug 4 regression tests (Phase 0.5 wire-up + cleanup f-1/f-2/f-3)
+// ---------------------------------------------------------------
+
+test('ultracontinue Bug 4 — Phase 0.5 documents cleanup mode dispatch', () => {
+  const cmd = readCommand();
+  assert.match(cmd, /## Phase 0\.5 /, 'Phase 0.5 header must be present');
+  // Phase 0.5 must come BETWEEN Phase 0 and Phase 1.
+  const idx05 = cmd.indexOf('## Phase 0.5 ');
+  const idx1 = cmd.indexOf('## Phase 1 ');
+  assert.ok(idx05 !== -1 && idx1 !== -1 && idx05 < idx1,
+    'Phase 0.5 must appear before Phase 1');
+  // Must reference cleanupProject and parsed flags['--cleanup'].
+  const phase05 = extractPhase(cmd, '## Phase 0.5 ');
+  assert.match(phase05, /cleanupProject/, 'Phase 0.5 must invoke cleanupProject');
+  assert.match(phase05, /flags\['--cleanup'\]/, "Phase 0.5 must dispatch via flags['--cleanup']");
+  // Usage block must document both forms.
+  assert.match(cmd, /--cleanup --confirm/, 'usage must mention --cleanup --confirm');
+});
+
+test('ultracontinue Bug 4 (f-1) dry-run lists candidates without deleting', async () => {
+  const { cleanupProject } = await import('../../lib/util/cleanup.mjs');
+  const root = mkdtempSync(join(tmpdir(), 'ultracontinue-cleanup-'));
+  try {
+    const dir = join(root, 'project-completed');
+    mkdirSync(dir, { recursive: true });
+    writeFileSync(join(dir, '.session-state.local.json'), JSON.stringify({
+      schema_version: 1,
+      project: dir,
+      next_session_brief_path: join(dir, 'brief.md'),
+      next_session_label: 'Done',
+      status: 'completed',
+      updated_at: '2026-05-04T16:00:00.000Z',
+    }, null, 2));
+    writeFileSync(join(dir, 'NEXT-SESSION-PROMPT.local.md'),
+      '---\nproduced_by: ultraexecute-local\nproduced_at: 2026-05-04T16:00:00.000Z\n---\n\n# Done\n');
+    const r = cleanupProject(dir, { dryRun: true });
+    assert.equal(r.valid, true, JSON.stringify(r.errors));
+    assert.equal(r.parsed.wouldDelete.length, 2);
+    assert.equal(readFileSync(join(dir, '.session-state.local.json'), 'utf8').length > 0, true);
+    assert.equal(readFileSync(join(dir, 'NEXT-SESSION-PROMPT.local.md'), 'utf8').length > 0, true);
+  } finally {
+    rmSync(root, { recursive: true, force: true });
+  }
+});
+
+test('ultracontinue Bug 4 (f-2) confirm deletes and (f-3) idempotent re-run handles already-clean dir', async () => {
+  const { cleanupProject } = await import('../../lib/util/cleanup.mjs');
+  const { existsSync } = await import('node:fs');
+  const root = mkdtempSync(join(tmpdir(), 'ultracontinue-cleanup-'));
+  try {
+    const dir = join(root, 'project-completed');
+    mkdirSync(dir, { recursive: true });
+    writeFileSync(join(dir, '.session-state.local.json'), JSON.stringify({
+      schema_version: 1,
+      project: dir,
+      next_session_brief_path: join(dir, 'brief.md'),
+      next_session_label: 'Done',
+      status: 'completed',
+      updated_at: '2026-05-04T16:00:00.000Z',
+    }, null, 2));
+    writeFileSync(join(dir, 'NEXT-SESSION-PROMPT.local.md'),
+      '---\nproduced_by: ultraexecute-local\nproduced_at: 2026-05-04T16:00:00.000Z\n---\n\n# Done\n');
+
+    // f-2: confirm deletes
+    const r2 = cleanupProject(dir, { dryRun: false, confirm: true });
+    assert.equal(r2.valid, true, JSON.stringify(r2.errors));
+    assert.equal(r2.parsed.deleted.length, 2);
+    assert.equal(existsSync(join(dir, '.session-state.local.json')), false);
+    assert.equal(existsSync(join(dir, 'NEXT-SESSION-PROMPT.local.md')), false);
+
+    // f-3: idempotent re-run on a fully-cleaned dir reports CLEANUP_NO_STATE_FILE
+    // (no state file → nothing to clean) — a deterministic terminal signal,
+    // not a crash. Operators can ignore it.
+    const r3 = cleanupProject(dir, { dryRun: false, confirm: true });
+    assert.equal(r3.valid, false);
+    assert.ok(r3.errors.find(e => e.code === 'CLEANUP_NO_STATE_FILE'));
+  } finally {
+    rmSync(root, { recursive: true, force: true });
+  }
+});