build(frontend): close the lint gaps the E32 audit measured

eslint now also enforces:
- the React Compiler diagnostics that `recommended` leaves out (todo,
  memo-dependencies and ten zero-hit tripwires);
- a description on every suppression, and no blanket disables;
- no focused or skipped tests (vitest and playwright);
- the typed pair no-floating-promises and no-deprecated.

Lint also covers e2e/ and the TypeScript build configs, which `eslint .`
had been skipping in silence.

Every hit is fixed or suppressed inline with a named reason:
- The 31 try statements the compiler cannot lower yet carry a suppression
  until S3 rewrites them. Five other compiler skips were plain fixes:
  a module counter bumped inside a hook, a ref read in a default
  parameter, and a local named like the <section> it renders.
- The real defects behind floating promises are fixed. ChatDock threw at
  nobody when the device key store could not be opened. VideoEditor's
  play() rejection went unhandled. loadYouTubeApi never rejected, so a
  blocked IFrame API left the player on an empty stage forever; it now
  fails on a script error or after 15 s, shows its own error with the
  way out, and lets the next open try again.
- MutableRefObject, FormEvent and lucide's deprecated brand icon are
  replaced. The YouTube glyph now lives in lib/brandIcons.
- The lint-probe harness lets its virtual file names into TypeScript's
  default project, so the contract tests still run the real config.

frontend/tsconfig.node.json

@@ -24,21 +24,24 @@
     "noUnusedParameters": true,
     "noFallthroughCasesInSwitch": true,
     "resolveJsonModule": true,
-    // The build-tool configs include two hand-written .js files (tailwind/postcss). checkJs runs
-    // the type checker over them via their `@type` JSDoc, so a bad tailwind/postcss option is
-    // caught by the gate instead of silently mis-building CSS. Was the last hole in C-4.5.
+    // The build-tool configs include a hand-written .js file (postcss; tailwind 4 needs no config
+    // file, and the stale `tailwind.config.js` entry pointed at nothing until E32). checkJs runs
+    // the type checker over it via its `@type` JSDoc, so a bad option is caught by the gate instead
+    // of silently mis-building CSS. Was the last hole in C-4.5.
     "allowJs": true,
     "checkJs": true
   },
   // reactPlugin.ts is the ONE React transform both configs import (E27 S1) — it is build tooling,
   // not app source, so it belongs here and not under tsconfig.json's ["src"]. A file imported by a
-  // listed one but absent from `include` is TS6307, not a silent pass.
+  // listed one but absent from `include` is TS6307, not a silent pass. playwright.config.ts is
+  // here as well as in e2e/tsconfig.json because eslint's typed rules (E32) find a file's project
+  // through tsconfig.json's `references`, which name this project and not the e2e one.
   "include": [
     "vite.config.ts",
     "vitest.config.ts",
     "reactPlugin.ts",
     "devOnlyGuard.ts",
-    "tailwind.config.js",
+    "playwright.config.ts",
     "postcss.config.js"
   ]
 }