feat(cli): add --latest, --debug, --role flags to live command (#37 Phase 2)

- --latest: auto-find most recent thread by start timestamp
- --debug: display .info.jsonl debug log with tags
- --role: filter output to specific role
- Add live-argv.ts for flag parsing
- Add fixtures and test coverage for all flags

Testing: #50

packages/workflow/src/fork-thread.ts

@@ -1,6 +1,6 @@
 import { normalizeRefsField } from "./refs-field.js";
 import { err, ok, type Result } from "./result.js";
-import type { RoleOutput, WorkflowResult } from "./types.js";
+import type { RoleOutput, WorkflowCompletion } from "./types.js";
 
 /** Role steps replayed from `.data.jsonl`, including persisted timestamps. */
 export type ForkHistoricalStep = RoleOutput & { timestamp: number };
@@ -14,8 +14,10 @@ export type ParsedThreadStartRecord = {
   depth: number;
 };
 
-/** Recognizes a persisted workflow completion line (no `role`; has numeric `returnCode` and string `summary`). */
-export function tryParseWorkflowResultRecord(obj: Record<string, unknown>): WorkflowResult | null {
+/** Recognizes a persisted workflow completion line (no `role`; has numeric `returnCode` and string `summary`). Omits `rootHash` when absent. */
+export function tryParseWorkflowResultRecord(
+  obj: Record<string, unknown>,
+): WorkflowCompletion | null {
   if (obj.role !== undefined) {
     return null;
   }

packages/workflow/src/worker.ts

@@ -422,7 +422,7 @@ async function main(): Promise<void> {
     } catch (e) {
       const message = e instanceof Error ? e.message : String(e);
       bootLog("Q3MN8YKW", `thread ${threadId} failed: ${message}`);
-      const failure: WorkflowResult = { returnCode: 1, summary: message };
+      const failure: WorkflowResult = { returnCode: 1, summary: message, rootHash: "" };
       await appendFile(dataJsonlPath, `${JSON.stringify(failure)}\n`, "utf8").catch(() => {});
     } finally {
       threads.delete(threadId);