opentui(ts): type-aware eslint (projectService + recommendedTypeChecked); defer cast-family to warn

Enable type-aware linting in ui-tui-opentui-v2: add projectService +
tsconfigRootDir to the TS files block and switch the preset to
recommendedTypeChecked. Turn ON as ERROR the high-value promise rules
(no-floating-promises, no-misused-promises, await-thenable) and fix the
3 real floating-promise sites in the gateway client (FileSink
write/flush/end are fire-and-forget on a piped child stdin — marked
with explicit `void`).

Defer the cast/unknown family + the noisy type-checked rules to 'warn'
(gate stays green; eslint exits 0 on warnings) for Phase 2, which will
replace the `as`/`unknown` boundary casts with Schema decoding:
no-unsafe-{assignment,member-access,argument,return,call},
no-unnecessary-condition, no-base-to-string, restrict-template-
expressions, no-unnecessary-type-assertion, require-await.

ui-tui-opentui-v2/eslint.config.mjs

@@ -7,9 +7,15 @@ export default tseslint.config(
     ignores: ["node_modules/**", "dist/**", ".repos/**", "*.frame.txt", "*.ansi"],
   },
   js.configs.recommended,
-  ...tseslint.configs.recommended,
+  ...tseslint.configs.recommendedTypeChecked,
   {
     files: ["**/*.ts", "**/*.tsx"],
+    languageOptions: {
+      parserOptions: {
+        projectService: true,
+        tsconfigRootDir: import.meta.dirname,
+      },
+    },
     plugins: {
       "unused-imports": unusedImports,
     },
@@ -23,6 +29,37 @@ export default tseslint.config(
         "warn",
         { vars: "all", varsIgnorePattern: "^_", args: "after-used", argsIgnorePattern: "^_" },
       ],
+
+      // --- Type-aware, high-value: ON as ERROR ---
+      "@typescript-eslint/no-floating-promises": "error",
+      "@typescript-eslint/no-misused-promises": "error",
+      "@typescript-eslint/await-thenable": "error",
+
+      // --- Phase 2: promote to error after Schema decode replaces the casts ---
+      // The cast/`unknown` family fires on the `as`/`unknown` boundary code that
+      // Phase 2 will replace with Schema decoding. Deferred to 'warn' so the gate
+      // stays green (eslint exits 0 on warnings) without masking the real signal.
+      "@typescript-eslint/no-unsafe-assignment": "warn",
+      "@typescript-eslint/no-unsafe-member-access": "warn",
+      "@typescript-eslint/no-unsafe-argument": "warn",
+      "@typescript-eslint/no-unsafe-return": "warn",
+      "@typescript-eslint/no-unsafe-call": "warn",
+      "@typescript-eslint/no-unnecessary-condition": "warn",
+      "@typescript-eslint/no-base-to-string": "warn",
+      "@typescript-eslint/restrict-template-expressions": "warn",
+      // `no-unnecessary-type-assertion` is the cast family (the one site is a
+      // `effect as Effect.Effect<…>` test cast); `require-await` fires only on
+      // async test-mock fns satisfying an async signature. Both are recommended
+      // -TypeChecked errors by default — demote to 'warn' to keep the gate green
+      // until Phase 2 (Schema decode) removes the casts.
+      "@typescript-eslint/no-unnecessary-type-assertion": "warn",
+      "@typescript-eslint/require-await": "warn",
     },
   },
+  {
+    // The eslint flat config is JS-only; the typed parser project service does not
+    // cover it, so disable type-checking there to avoid parser errors.
+    files: ["eslint.config.mjs"],
+    ...tseslint.configs.disableTypeChecked,
+  },
 )

ui-tui-opentui-v2/src/boundary/gateway/client.ts

@@ -227,8 +227,11 @@ export class RawGatewayClient {
       })
 
       try {
-        stdin.write(frame)
-        stdin.flush()
+        // FileSink.write/flush type as `number | Promise<number>`; for a piped
+        // child stdin they return synchronously — this is intentional
+        // fire-and-forget (no backpressure await), so mark the intent explicitly.
+        void stdin.write(frame)
+        void stdin.flush()
       } catch (cause) {
         this.pending.delete(id)
         clearTimeout(timer)
@@ -250,7 +253,8 @@ export class RawGatewayClient {
     const stdin = this.proc?.stdin
     if (stdin && typeof stdin !== 'number') {
       try {
-        stdin.end()
+        // Fire-and-forget EOF: FileSink.end types as `number | Promise<number>`.
+        void stdin.end()
       } catch {
         // already gone
       }