feat(rewrite): bootstrap monorepo Bun + port domain layer ke TypeScript

Mulai migrasi Zesdex dari Rust ke TypeScript/Bun.

- Root workspace package.json, tsconfig strict, bun.lock, gitignore fix
- Paket @zesdex/domain (apps/packages/domain):
  - core: ChatMessage/Conversation/ToolCall/SseParser/repairJson/
    sanitizeToolArguments/UsageStats/Store/DomainError
  - auth: Session/SessionId/SessionLock/OAuth + repository & service interfaces
  - cms: AppConfig/Settings/SettingsPatch/Memory/EditLog + repository &
    service interfaces
  - agent: TurnEvent/SessionRuntime/AgentTurnParams/AgentProgress/prompt
  - subagent & workflow models
- Wire-shape JSON disamakan dengan Rust (serde rename/flatten/skip_if)
- 27 unit test Bun port dari test Rust (SseParser, repair_json, resolve_effective_model, session id)

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

apps/packages/domain/src/index.ts

@@ -0,0 +1,10 @@
+/**
+ * Zesdex Domain Layer — pure types, value objects, and port interfaces.
+ * Zero framework dependencies, zero I/O. Mirrors the Rust `zesdex-domain` crate.
+ */
+export * from "./core/index.ts";
+export * from "./auth/index.ts";
+export * from "./cms/index.ts";
+export * from "./agent/index.ts";
+export * from "./subagent/mod.ts";
+export * from "./workflow/mod.ts";