feat(rewrite): tambah infrastructure — LLM client + full file persistence

Sub-fase 3a & 3e infrastructure TypeScript (@zesdex/infrastructure):
- llm/provider.ts: LlmClient (OpenAI/Anthropic-compatible fetch + SSE,
  retry 10x exponential backoff + jitter, abort on 401/402/403,
  stream quota-aware tool-call delta accumulation)
- resolveApiKey: settings.api_keys → app_config.env_var → inline default
- utils: writeJsonAtomic (tmp+rename+fsync), slugify, writeOsc52,
  truncateChars, buildWorkspaceTree, runCommand
- persistence/cms: JsonSettingsRepository, JsonAppConfigRepository
  (Claude credential auto-detection dari ~/.claude/settings.json + env),
  JsonConversationRepository, JsonlEditLogRepository (append NDJSON),
  MarkdownMemoryRepository (YAML-ish frontmatter), FileRewindBlobRepository
- persistence/iam: FileSystemSessionRepository, FileSystemSessionLockRepository,
  FileSystemOAuthRepository
- Workspace @zesdex/infrastructure tsc clean, semua test domain+application
  tetap hijau (38 pass)

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

apps/packages/infrastructure/package.json

@@ -0,0 +1,22 @@
+{
+  "name": "@zesdex/infrastructure",
+  "version": "1.21.2",
+  "private": true,
+  "type": "module",
+  "description": "Zesdex infrastructure layer — concrete adapters (LLM, tools, persistence, auth, MCP, IPC, workflow)",
+  "exports": {
+    ".": "./src/index.ts"
+  },
+  "scripts": {
+    "test": "bun test",
+    "typecheck": "tsc --noEmit"
+  },
+  "dependencies": {
+    "@zesdex/domain": "workspace:*",
+    "@zesdex/application": "workspace:*"
+  },
+  "devDependencies": {
+    "@types/bun": "^1.2.0",
+    "typescript": "^5.7.0"
+  }
+}