Add repository typecheck command

Summary

The repository now has a first-class typecheck gate. Running bun run typecheck checks every workspace TypeScript project under apps, services, and packages, reports failures per workspace, and exits non-zero if any project fails.

Changes Made

• Added scripts/typecheck.ts, a Bun runner that discovers workspace tsconfig.json files.
• Added the root typecheck package script.
• Added root development dependencies for typescript, @types/bun, and @types/ws.
• Updated workspace tsconfig.json files to include Bun runtime types instead of stripping all globals.
• Fixed type errors exposed by the new gate in tests, JetStream config, storage JSON decoding, API live fanout, and WebSocket payload decoding.

Context

Before this change, the desktop app had a local typecheck script, but the repository did not have a single command for checking the whole Bun and TypeScript monorepo. The first run surfaced both configuration issues and real type mismatches that were not visible from existing validation commands.

Important Implementation Details

The typecheck runner intentionally discovers workspace projects from the existing folder structure rather than maintaining a hard-coded list. It passes --incremental false so checking the Next.js workspace does not leave tracked tsconfig.tsbuildinfo churn behind.

Workspace configs now use "types": ["bun"]. This matches the runtime and test environment used by the repo while preserving explicit control over global types.

Relevant Diff Snippets

Attempted to use @pierre/diffs as requested by the repository instructions, but the installed package exposes library exports and no executable CLI. The snippets below are therefore the documented plain diff fallback.

diff --git a/package.json b/package.json
@@
     "deploy:current-branch": "./deploy current-branch",
+    "typecheck": "bun run scripts/typecheck.ts",
@@
   "devDependencies": {
+    "@types/bun": "^1.3.3",
+    "@types/ws": "^8.18.1",
+    "typescript": "^5.9.3",
     "typescript-language-server": "^5.1.3"
   }

diff --git a/scripts/typecheck.ts b/scripts/typecheck.ts
+const workspaceRoots = ["apps", "services", "packages"];
+const tsconfigs = workspaceRoots.flatMap((root) => findTsconfigs(root)).sort();
+
+for (const tsconfig of tsconfigs) {
+  const result = Bun.spawnSync([
+    "bunx",
+    "tsc",
+    "-p",
+    tsconfig,
+    "--noEmit",
+    "--incremental",
+    "false",
+    "--pretty",
+    "false"
+  ]);
+}

diff --git a/packages/bus/src/jetstream.ts b/packages/bus/src/jetstream.ts
@@
-  retention: "limits",
-  storage: "file",
-  discard: "old",
+  retention: RetentionPolicy.Limits,
+  storage: StorageType.File,
+  discard: DiscardPolicy.Old,

diff --git a/packages/bus/tsconfig.json b/packages/bus/tsconfig.json
@@
-    "types": []
+    "types": ["bun"]

Expected Impact for End-Users

Developers now have one obvious command to validate TypeScript correctness before handoff or deployment: bun run typecheck. This should catch drift across shared packages and services earlier, especially when changes cross workspace boundaries.

Validation

• bun run typecheck passed across all discovered workspace tsconfig.json files.
• bun test passed: 250 tests, 0 failures, 994 assertions.
• Confirmed the typecheck script no longer modifies apps/web/tsconfig.tsbuildinfo.

Issues, Limitations, and Mitigations

The command checks workspace TypeScript projects that already have a tsconfig.json. If a new workspace is added without a config file, it will not be checked until that config exists. The runner prints each checked config path to make coverage visible during validation.

Follow-up Work

No required follow-up remains for this task. A useful future improvement would be adding the new typecheck command to CI once the Forgejo pipeline is ready for a broader quality gate.