feat: TypeScript SDK (agentlens-sdk) and OpenCode plugin (opencode-agentlens)

- packages/sdk-ts: BatchTransport, TraceBuilder, models, decision helpers
  Zero external deps, native fetch, ESM+CJS output
- packages/opencode-plugin: OpenCode plugin with hooks for:
  - Session lifecycle (create/idle/error/delete/diff)
  - Tool execution capture (before/after -> TOOL_CALL spans + TOOL_SELECTION decisions)
  - LLM call tracking (chat.message -> LLM_CALL spans with model/provider)
  - Permission flow (permission.ask -> ESCALATION decisions)
  - File edit events
  - Model cost estimation (Claude, GPT-4o, o3-mini pricing)

packages/sdk-ts/tsup.config.ts

@@ -0,0 +1,9 @@
+import { defineConfig } from "tsup";
+
+export default defineConfig({
+  entry: ["src/index.ts"],
+  format: ["esm", "cjs"],
+  dts: true,
+  clean: true,
+  sourcemap: true,
+});