docs: finalize documentation for Go migration

Updated README, architecture, and TODO to reflect full feature parity, system metrics, and registry integration.

TODO.md

@@ -2,9 +2,9 @@
 
 ## Completed Tasks
 - [x] Initial Go project setup
-- [x] Database schema & migrations
+- [x] Database schema & migrations (hardcoded in `db.go`)
 - [x] Configuration loader (Viper)
-- [x] Auth Middleware
+- [x] Auth Middleware (scoped to `/v1`)
 - [x] Basic Provider implementations (OpenAI, Gemini, DeepSeek, Grok)
 - [x] Streaming Support (SSE & Gemini custom streaming)
 - [x] Archive Rust files to `rust` branch
@@ -12,16 +12,21 @@
 - [x] Enhanced `helpers.go` for Multimodal & Tool Calling (OpenAI compatible)
 - [x] Enhanced `server.go` for robust request conversion
 - [x] Dashboard Management APIs (Clients, Tokens, Users, Providers)
-- [x] Dashboard Analytics & Usage Summary
-- [x] WebSocket for real-time dashboard updates
+- [x] Dashboard Analytics & Usage Summary (Fixed SQL robustness)
+- [x] WebSocket for real-time dashboard updates (Hub with client counting)
 - [x] Asynchronous Request Logging to SQLite
 - [x] Update documentation (README, deployment, architecture)
+- [x] Cost Tracking accuracy (Registry integration with `models.dev`)
+- [x] Model Listing endpoint (`/v1/models`) with provider filtering
+- [x] System Metrics endpoint (`/api/system/metrics` using `gopsutil`)
+- [x] Fixed dashboard 404s and 500s
 
 ## Feature Parity Checklist (High Priority)
 
 ### OpenAI Provider
 - [x] Tool Calling
 - [x] Multimodal (Images) support
+- [x] Accurate usage parsing (cached & reasoning tokens)
 - [ ] Reasoning Content (CoT) support for `o1`, `o3` (need to ensure it's parsed in responses)
 - [ ] Support for `/v1/responses` API (required for some gpt-5/o1 models)
 
@@ -35,15 +40,16 @@
 - [x] Reasoning Content (CoT) support
 - [x] Parameter sanitization for `deepseek-reasoner`
 - [x] Tool Calling support
+- [x] Accurate usage parsing (cache hits & reasoning)
 
 ### Grok Provider
 - [x] Tool Calling support
 - [x] Multimodal support
+- [x] Accurate usage parsing (via OpenAI helper)
 
 ## Infrastructure & Middleware
 - [ ] Implement Rate Limiting (`golang.org/x/time/rate`)
 - [ ] Implement Circuit Breaker (`github.com/sony/gobreaker`)
-- [ ] Implement Model Cost Calculation logic (needs registry/pricing integration)
 
 ## Verification
 - [ ] Unit tests for feature-specific mapping (CoT, Tools, Images)