query_project: implement the standup view (#28)

The StandupScreen already renders drift + plan + nag from real data (standup-view,
#52), but the agent's query_project standup view was a `notImplemented` stub, so
Reginald couldn't answer standup questions from deterministic data.

Implement `standupView(snap, asOf)`: today's plan (the scheduler's earliest pick
per person, with why — critical path / blocks / order), overnight drift (real
anomalies: issues sitting in review, or steeping past their estimate), and the
single stalest blocker to nag about (+ what it blocks). All deterministic; the
model narrates. Added 'standup' to the query_project tool's view enum.

Acceptance met: standup surfaces schedule drift + at least one stale blocker
(and stays calm — no nag, empty drift — when nothing is steeping). +2 core tests;
typecheck clean.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packages/core/src/agent/agent-tools.ts

@@ -17,10 +17,11 @@ export const QUERY_PROJECT_TOOL: ToolDecl = {
     properties: {
       view: {
         type: 'string',
-        enum: ['focus', 'board', 'calibration', 'issue', 'search'],
+        enum: ['focus', 'board', 'calibration', 'issue', 'search', 'standup'],
         description:
           'focus = Now/Next/Later; board = issues by lifecycle column; calibration = estimate-vs-actual; ' +
-          'issue = one issue (needs filters.issueId); search = issues matching filters.query.',
+          'issue = one issue (needs filters.issueId); search = issues matching filters.query; ' +
+          "standup = today's plan + overnight drift + the stalest blocker.",
       },
       filters: {
         type: 'object',