feat(metrics): publish timeseries.json + dashboard schema additions

[zacharias-ona]

Problem

software-factory.dev's /dashboard route is being migrated from a static
HTML file to a Next.js page that consumes a single time-series file from
this repository. The dashboard needs three pieces of data not currently
in metrics/daily/*.json: test counts, daily issues-opened/closed deltas,
and PR/issue latency distributions.

Closes #862

Change

1. Daily snapshots gain five new fields: tests, issues.delta_done,
   issues.delta_opened, pr_merge_time_buckets, issue_close_time_buckets.
2. New aggregator (scripts/metrics/build-timeseries.mjs) publishes metrics/timeseries.json on every daily run.
3. Backfilled Apr 14–29 with measured values from GitHub API and git history
   (test counts from historical worktrees, issue/PR deltas from API,
   cumulative latency distributions from actual merge/close times).
4. Updated daily-metrics automation to collect new fields and run aggregator
   as final step.

The aggregator is idempotent: re-running it produces a byte-identical
file modulo updatedAt. A schema-guard helper validates the top-level
and per-day key sets before write.

Sample diff (one daily snapshot)

 {
   "date": "2026-04-28",
   "day_number": 16,
   "loc": { "total": 64546, "delta": 1619, "by_language": { ... } },
   "prs": { "total": 465, "delta": 0, "currently_open": 0 },
   "commits": { "total": 488, "delta": 0 },
   "test_coverage_pct": 38.35,
   "autonomous_pct": 85,
-  "issues": { "backlog": 0, "in_progress": 0, "in_review": 0, "done": 343 },
+  "issues": {
+    "backlog": 0, "in_progress": 0, "in_review": 0, "done": 343,
+    "delta_done": 1, "delta_opened": 1
+  },
+  "tests": { "unit": 1591, "e2e": 290 },
+  "pr_merge_time_buckets":    { "lt_5m": 206, "5_10m": 177, "10_20m": 54, "30_60m": 24, "1_2h": 10 },
+  "issue_close_time_buckets": { "lt_15m": 49, "15_30m": 81, "30_60m": 101, "1_2h": 66, "2_4h": 44, "4_8h": 16 },
   "human_minutes": null,
   "agent_minutes": null
 }

Validation

• metrics/timeseries.json parses; top-level keys are exactly
  ["updatedAt", "startDate", "days", "latest"].
• Per-day entries have exactly the nine keys documented in the schema.
• No date gaps between Apr 14 and the most recent snapshot.
• Aggregator is idempotent (proven by running it twice and diffing).
• Existing daily fields are byte-unchanged for past dates.
• Lint, typecheck, and all 1730 unit tests pass.

Consumer: https://github.com/gitpod-io/software-factory.dev

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Project	Deployment	Actions	Updated (UTC)
memo	Ready	Preview, Comment	Apr 29, 2026 9:59pm

[sw-factory-automations]

✅ UI verification skipped — no UI files changed.

Changed files are limited to metrics/daily/*.json, metrics/timeseries.json, scripts/metrics/build-timeseries.mjs, and .ona/automations/daily-metrics.yaml. None match src/components/*, src/app/**/page.tsx, or src/app/**/layout.tsx.

[sw-factory-automations]

✅ Post-merge verification passed.

E2E suite against live site: 286/293 passed (8 did not run).

• 6 failures are pre-existing and unrelated to this PR (account-deletion, database-csv-export, favorites, trash, version-history, workspace-limit, workspace-settings). This PR only modifies metrics data files, a build script, and automation config — no UI, pages, or API routes were changed.
• 1 visual-regression skip (expected — no Storybook server for live site runs).

Ad-hoc smoke tests: All passed.

Route	Result
/ (landing page)	✅ Loaded, has title
/sign-in	✅ Email input present
/api/health	✅ Healthy
/dashboard	Skipped (not yet built)
Authenticated login flow	✅ Sign-in → workspace redirect
Workspace page	✅ Loaded
Editor navigation	Skipped (no page buttons in test workspace)

Interaction smoke test: N/A — this PR adds metrics data files and a build script consumed by an external site (software-factory.dev), not by memo.software-factory.dev. No UI components or pages were modified.