feat: add pricing sync script and update model prices from OpenRouter (#27)

* fix: pin npm package versions in MCP integration templates

Prevent supply chain attacks by pinning exact versions instead of
using unpinned `npx -y @package` which pulls latest on every run.

23 of 25 integrations pinned. sqlite-mcp and aws skipped (packages
not found on npm registry).

* fix: use stable azure/mcp version instead of beta

* feat: add pricing sync script and update model prices from OpenRouter API

- scripts/sync-pricing.py fetches real-time pricing from OpenRouter
- Updated 64 price fields across 13 provider files
- Run periodically or in CI to keep prices current

providers/xai.toml

@@ -79,8 +79,8 @@ display_name = "Grok 3"
 tier = "frontier"
 context_window = 131072
 max_output_tokens = 32768
-input_cost_per_m = 3.0
-output_cost_per_m = 15.0
+input_cost_per_m = 0.3
+output_cost_per_m = 0.5
 supports_tools = true
 supports_vision = true
 supports_streaming = true