build(frontend)!: knip drops --production; plain knip stays

The production pass (7ed2ac4e, E32) asked "is this export used by what
ships?". No real hit: its only findings were 37 exports a test imports,
answered with 36 `@internal` JSDoc tags (E34 S2) — test-only exports, not
defects. Since then it has only ever asked for another tag. The tags go
with it (36, no longer read by anything), and so do the production-only
`!…!` exclusions in knip.jsonc and their register rows. Plain knip (unused
files, exports and dependencies) keeps running in the gate.

docs/development.md

@@ -97,7 +97,7 @@ node ../scripts/check-node-modules.mjs   # node_modules == package-lock.json (el
 npm run typecheck     # tsc x3 (app / node / e2e)
 npm run lint          # eslint (typed rules included; warnings fail)
 npm run format:check  # prettier
-npm run knip          # unused files/exports/deps — and unused by what SHIPS (--production)
+npm run knip          # unused files/exports/deps
 npm run test          # vitest (incl. the compiler and gate-register contracts)
 npx vite build        # the production bundle (devOnlyGuard fails it on dev-only code)
 npm audit --omit=dev --audit-level=high   # what ships to the browser, at high or above

docs/gates.md

@@ -103,14 +103,6 @@ project checks needs a row.
 | --- | --- | --- | --- |
 | a hand run | `SIFTLODE_TEST_REQUIRE_DB=0` — the DB-backed and ffmpeg tests skip | The explicit "pure-logic only" run for a machine without Postgres. Off by default since E32: without it a missing DB is a hard error; the gate and CI never set it. | — |
 
-## knip (frontend)
-
-| Scope | Narrowed | Why | Measured |
-| --- | --- | --- | --- |
-| --production | `!**/*.testkit.ts!`, `!e2e/**!` | Test kits and the e2e suite are test code: the production pass asks what the SHIPPED code uses. | — |
-| --production | `!reactPlugin.ts!`, `!devOnlyGuard.ts!` | Build tooling the vite config imports: it shapes the bundle but is not in it. | — |
-| --production | `@internal` exports | An export only its test imports says so with a JSDoc `@internal` tag naming the test; knip skips those in production mode. | 35 (E32 S1) |
-
 ## Lanes and pipeline
 
 | Scope | Narrowed | Why | Measured |