test(cli,tui): add in-process source coverage gates (#1484) (#1502)

* test(cli,tui): add in-process source coverage gates (#1484)

CLI and TUI source had no coverage gate: CLI tests spawned the built
binary out-of-process (coverage never saw clients/cli/src) and the TUI
had only two smoke tests. Regressions there were invisible to CI.

CLI:
- Rewrite __tests__/helpers/cli-runner.ts to invoke runCli() in-process
  (capture process.std*.write, map thrown errors to an exit code),
  preserving the CliResult shape so all existing tests run unchanged and
  clients/cli/src is now measured under v8 instrumentation.
- cli.ts: program.exitOverride() so a commander usage error throws
  (catchable in-process) instead of tearing down the worker; --help /
  --version still exit cleanly. Drop the dead, never-imported main().
- Add a thin out-of-process e2e.test.ts that spawns the built binary for
  the shebang / process.exit paths the in-process runner can't reach.
- Add @vitest/coverage-v8, a per-file gate (90/85/80/50) excluding only
  src/index.ts (binary bootstrap), and pool: 'forks' for capture
  isolation. cli.ts lands at ~98% lines / 100% functions.

TUI:
- Add @vitest/coverage-v8 and an interim per-file gate over the
  non-React logic (logger.ts, components/tabsConfig.ts, utils/*); the
  Ink components, App.tsx, and hooks/ are excluded with a documented
  follow-up (#1501). Add tests covering the included modules (100%).

Wiring + docs:
- CI runs each client's test:coverage; root test:cli / test:tui (used by
  validate) and root test:coverage now enforce the gates.
- gitignore clients/**/coverage; update AGENTS.md and client READMEs.

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

* docs(cli): clarify in-process runner footguns from PR #1502 review

Review notes on the in-process CLI test runner (no behavior change):
- Warn in runCli's docblock that --help/--version must NOT go through the
  in-process runner: exitOverride only re-throws non-zero exits, so exitCode
  0 falls through to process.exit(0) and would kill the vitest worker. Those
  belong in the out-of-process e2e.test.ts layer.
- Document that a timeout orphans the uncancellable invokeCli promise (its
  stdio subprocess stays alive; later writes hit the restored stdout) — a
  known, acceptable trade-off on the hang-only failure path.
- Fix a stale reference to the removed main() (errors now route through
  index.ts).

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

* docs(cli): fix remaining stale main() reference in vitest exclusion comment

PR #1502 re-review caught a second stale `main()` mention (the first was
fixed in 52c23e41). src/index.ts inlines the bootstrap as
runCli(process.argv).then(...).catch(handleError) — there is no main().
Comment-only; no behavior change.

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

* chore: compose root test:coverage from per-client scripts

Replace the brittle inline cd-chain with a composition of the existing
test:cli / test:tui scripts plus a new matching test:web. Behavior is
unchanged (web → cli → tui coverage gates) but there's a single source of
truth for each client's coverage invocation.

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

---------

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

package.json

@@ -35,8 +35,9 @@
     "build:tui": "cd clients/tui && npm run build",
     "build:launcher": "cd clients/launcher && npm run build",
     "prepack": "npm run build",
-    "test:cli": "cd clients/cli && npm run test",
-    "test:tui": "cd clients/tui && npm run test",
+    "test:web": "cd clients/web && npm run test:coverage",
+    "test:cli": "cd clients/cli && npm run test:coverage",
+    "test:tui": "cd clients/tui && npm run test:coverage",
     "validate": "npm run validate:web && npm run test:cli && npm run test:tui && npm run validate:launcher",
     "validate:web": "cd clients/web && npm run validate",
     "validate:launcher": "npm run build:cli && npm run build:tui && npm run build:launcher && npm run smoke:launcher && npm run smoke:cli && npm run smoke:tui && npm run smoke:web",
@@ -45,7 +46,7 @@
     "smoke:tui": "node scripts/smoke-tui.mjs",
     "smoke:web": "node scripts/smoke-web.mjs",
     "test": "cd ./clients/web/ && npm run test && cd ../cli && npm run test && cd ../tui && npm run test",
-    "test:coverage": "cd ./clients/web/ && npm run test:coverage",
+    "test:coverage": "npm run test:web && npm run test:cli && npm run test:tui",
     "test:storybook": "cd ./clients/web/ && npm run test:storybook",
     "inspector": "node clients/launcher/build/index.js",
     "web": "node clients/launcher/build/index.js --web",