refactor(tests): centralize lane definitions and add per-file isolation

- extract test lane config to scripts/test-lanes.ts (single source of truth)
- run-test-lane.mjs: per-file bun process isolation with wall timeout; --jobs N, --single-process flags
- drop hand-listed test file lists from package.json; lanes now discovered by directory
- add test:stats (stats/src) and test:scripts (scripts/**) lanes; wire both into CI
- test:fast now: test:src + launcher-unit + test:scripts + test:runtime:compat
- remove obsolete test:full, test:core, test:core:dist, test:config:dist scripts

docs/workflow/verification.md

@@ -3,10 +3,22 @@
 # Verification
 
 Status: active  
-Last verified: 2026-05-23  
+Last verified: 2026-07-06  
 Owner: Kyle Yasuda  
 Read when: selecting the right verification lane for a change
 
+## Lane Infrastructure
+
+- Lane membership is defined once in `scripts/test-lanes.ts` and discovered by
+  directory — new test files join their lane automatically; never hand-list test
+  files in `package.json`.
+- `scripts/run-test-lane.mjs` runs each test file in its own `bun test` process
+  (per-file isolation with a wall timeout) so a hanging test or leaked global in
+  one file cannot cascade into the rest of the lane. `--jobs N` parallelizes;
+  `--single-process` restores the shared-process mode for debugging.
+- `bun run test:fast` is the full source gate: discovered `src/**`, launcher
+  unit, `scripts/**`, and the compiled runtime-compat slice.
+
 ## Default Handoff Gate
 
 ```bash
@@ -31,6 +43,8 @@ bun run docs:build
 - Config/schema/defaults: `bun run test:config`, then `bun run generate:config-example` if template/defaults changed
 - Launcher/plugin: `bun run test:launcher` or `bun run test:env`
 - Runtime-compat / compiled behavior: `bun run test:runtime:compat`
+- Stats dashboard UI: `bun run test:stats`
+- Build/release scripts (`scripts/**`): `bun run test:scripts`
 - Coverage for the maintained source lane: `bun run test:coverage:src`
 - Deep/local full gate: default handoff gate above