fix(orchestration): refuse --retry-of beside --spec at the schema

--spec creates a new Task, so a retry link to a prior Dispatch could
never resolve; the refusal named a Task id the caller never supplied.
Refuse up front with the flag the caller needs, and say so in the help
note and the recovery reference.

skill-guides/orchestration/references/recovery-and-cleanup.md

@@ -109,8 +109,9 @@ optional.
 
 ## Retry, stop, and abandon
 
-Retry only a positively proven failed or stopped attempt. Placement is never
-silently inherited:
+Retry only a positively proven failed or stopped attempt. Name the failed Task
+with `--task`, since `--spec` creates a new one. Placement is never silently
+inherited:
 
 ```text
 ORCA orchestration worker-start --task <task_id> --retry-of <dispatch_id> --worktree <explicit_placement> --agent <agent> --json

src/cli/specs/orchestration-worker-specs.ts

@@ -39,7 +39,7 @@ export const ORCHESTRATION_WORKER_COMMAND_SPECS: CommandSpec[] = [
       'Creation flags (--name, --repo, --base-branch, --display-name, --comment, --setup) are rejected for current/existing worktrees. Use exact --repo on the selected server; project/host convenience routing remains on worktree create.',
       '--on selects only the worker server; the Run and this command remain on the current Orca server.',
       'Remote current and new-child are invalid; discover an exact remote selector or use new-top-level.',
-      '--retry-of links the replacement attempt but does not inherit placement; repeat the intended --on/worktree and --agent/terminal choices.',
+      '--retry-of needs --task naming the failed Task (--spec creates a new one) and does not inherit placement; repeat the intended --on/worktree and --agent/terminal choices.',
       'The call exits 0 only for ready. Failed or outcome_unknown exits 1 and JSON includes stage/failedStage, setup, effects, residualResources, and recovery commands when needed.'
     ]
   },

src/main/runtime/rpc/methods/orchestration/worker/worker-launch-preferences.test.ts

@@ -154,6 +154,27 @@ describe('orchestration worker launch preferences', () => {
     ).not.toThrow()
   })
 
+  it('refuses --retry-of beside --spec, which could only create a fresh Task', () => {
+    const parsed = WorkerStartParams.safeParse({
+      spec: 'redo it',
+      retryOf: 'ctx_prior',
+      agent: 'claude',
+      from: 'term_coord'
+    })
+    expect(parsed.success).toBe(false)
+    expect(parsed.error?.issues.map((issue) => issue.message)).toContain(
+      '--retry-of needs --task <task_id> naming the failed Task; --spec creates a new one'
+    )
+    expect(
+      WorkerStartParams.safeParse({
+        task: 'task_1',
+        retryOf: 'ctx_prior',
+        agent: 'claude',
+        from: 'term_coord'
+      }).success
+    ).toBe(true)
+  })
+
   it('uses the requested launch receipt when an older worker omits it', () => {
     const requested = createPendingWorkerLaunchReceipt({
       agent: 'codex',

src/main/runtime/rpc/methods/orchestration/worker/worker-start-schema.ts

@@ -48,6 +48,16 @@ export const WorkerStartParams = z
         message: '--task and --spec are mutually exclusive'
       })
     }
+    // Why: --spec creates a new Task, so a retry link to a prior Dispatch could never resolve and
+    // the refusal named a Task id the caller never supplied.
+    if (params.retryOf && params.spec) {
+      ctx.addIssue({
+        code: z.ZodIssueCode.custom,
+        path: ['retryOf'],
+        message:
+          '--retry-of needs --task <task_id> naming the failed Task; --spec creates a new one'
+      })
+    }
   })
 
 export type WorkerStartInput = z.infer<typeof WorkerStartParams>