docs: add handoff.md; note block/FSE test-data expansion in backlog

- handoff.md: living status doc; records the Phase 0 baseline, the deferred
  discover/route-parser gap, and the dev workflow.
- modernization-plan.md: backlog note to add a secondary block/FSE-oriented seed
  in phase 5 (the classic WXR predates the block editor), kept separate from the
  classic dataset that guards the wp/v2 regression net.

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

Author: kadamwhite

handoff.md

@@ -0,0 +1,58 @@
+# Modernization Handoff
+
+Living status doc for the node-wpapi modernization. See `modernization-plan.md`
+(vision) and `modernization-execution-plan.md` (phased plan). Trunk is `main`;
+each phase lands via a `--no-ff` merge.
+
+## Current state: Phase 0 complete (baseline green)
+
+Full suite green against the local wp-env WordPress:
+`805 passed, 16 skipped, 0 failed` (39 suites). No library/request logic changed
+except one isolated modern-WP compatibility fix (see below).
+
+### What Phase 0 did
+
+- **Local env is the integration target.** Tests now read the endpoint from
+  `tests/helpers/constants.js` (`WPAPI_HOST`, default `http://localhost:2747`),
+  replacing the old hardcoded `http://wpapi.local/wp-json`.
+- **Deterministic seed.** `npm run env:seed` empties the site, then imports
+  `tests/fixtures/theme-unit-test-data.xml` (the classic Theme Unit Test WXR).
+  `.wp-env.json` now also installs the `WP-API/Basic-Auth` plugin so the
+  authenticated tests work (modern WP core rejects plain Basic Auth).
+- **Refreshed expectations.** Integration assertions were updated for modern WP:
+  chiefly the WXR "Scheduled" post is now past-dated (today is 2026) and thus
+  published, shifting post counts/pagination; and modern WP default options
+  differ (empty tagline, extra settings keys). Only data values changed — no
+  test mechanic was loosened.
+- **Fixed:** `WPAPI.discover` read the root `_links.self` as a string; modern WP
+  returns `[ { href } ]`. Now accepts both (`lib/bind-transport.js`).
+
+### Known gap (deferred to Phase 5)
+
+- **`discover` / live-route bootstrap fails on modern WP.** The route-tree regex
+  parser (`lib/route-tree.js:83`) throws "Unterminated group" on routes whose
+  named groups contain nested patterns, e.g. `wp/v2/templates/(?P<id>...)`.
+  Default-mode instances are unaffected (they use the frozen
+  `lib/data/default-routes.json`). The `discover` integration suite is
+  `describe.skip`-ped with a `TODO(phase-5)`; its `beforeAll` `.catch()`es the
+  rejection so it can't leak into other suites. Fix the parser in Phase 5, then
+  un-skip and remove that `.catch()`.
+
+## Dev workflow
+
+```
+npm install
+npm run env:start     # boot wp-env (localhost:2747)
+npm run env:seed      # once, against a fresh env
+npm run test:unit     # no WP needed
+npm run test:integration
+```
+
+## Next: Phase 1 — modern toolchain (still JS)
+
+tsdown build (dual ESM+CJS+UMD, exports map), Jest -> Vitest, ESLint 9 flat +
+Prettier, Node 18+ / drop IE11, GitHub Actions CI. See execution plan Phase 1.
+
+Note for Phase 1/CI: integration tests currently pass both parallel and serial,
+but they share one DB. If CRUD suites prove flaky in CI, run integration with
+`--runInBand`.

modernization-plan.md

@@ -47,3 +47,29 @@ Get to "current baseline functionality, but working with modern WP", then move o
 Using the `gh` CLI, look through the issues backlog and make me a report of which can be closed (dependencies, vulnerabilities, etc), which deserve human responses (there's a lot of support requests so categorize as support, feature request, etc) and evaluate which are highest-value to action.
 
 NEVER UPDATE ISSUES DIRECTLY. Tell me recommendations, and I will execute.
+
+## Backlog notes
+
+### Expand the integration test-data set (Phase 5 sub-task, not urgent)
+
+The classic Theme Unit Test WXR (`tests/fixtures/theme-unit-test-data.xml`) predates the
+block editor: it's all classic-markup posts/pages/comments. It exercises the `wp/v2`
+content endpoints (posts, pages, media, taxonomies, pagination) well — exactly what the
+current integration suite asserts — so it remains fit as the Phase 0 regression net.
+
+It does not cover the modern surface Phase 5 targets: no block content, reusable blocks,
+templates/template-parts, global styles, navigation/menus, or font-family data. It won't
+meaningfully test the FSE/block-editor routes.
+
+When Phase 5 adds those route handlers, add a **secondary** block/FSE-oriented seed
+(keep the classic WXR as the stable baseline; don't replace it). Options to evaluate:
+
+- Gutenberg's own block-markup fixtures / E2E content (canonical block serialization).
+- WordPress/theme-test-data's block-based additions (check current state).
+- A `wp-cli` script that activates a block theme (Twenty Twenty-Four/Five) and seeds
+  templates, template-parts, global styles, `wp_block` reusable blocks, and a nav menu.
+  Stays maintainable and mirrors how modern WP state is actually created — recommended.
+- A small hand-authored block WXR committed as a second fixture.
+
+Recommendation: classic WXR proves we didn't regress; a block/FSE seed (likely the
+wp-cli-script approach) proves the new routes work. Keep the two concerns separate.