Add scout MCP server for browser recon + msgspec workspace dep

- tools/scout/: browser automation MCP server using Pydoll (CDP, no WebDriver)
  - scout_visit, scout_elements (text-first), scout_click, scout_fill, scout_select
  - scout_scroll, scout_text, scout_screenshot (opt-in)
  - scout_har_start / scout_har_stop (asyncio task holds recording context open)
  - scout_analyze: HAR parsing with HarEntry/HarSummary msgspec structs
  - Standalone project (not workspace member — websockets conflict with prefect)
  - Runs via: uv run --directory tools/scout scout-server

- .mcp.json: registers scout as Claude Code MCP server (project scope)

- msgspec>=0.19 added to root project deps (workspace-wide struct/validation)

- coding_philosophy.md: document msgspec as approved dep, usage rules

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

pyproject.toml

@@ -15,6 +15,7 @@ dependencies = [
     "niquests>=3.15.2",
     "hcloud>=2.8.0",
     "prefect>=3.6.15",
+    "msgspec>=0.19",
 ]
 
 [project.scripts]
@@ -43,7 +44,6 @@ sqlmesh_materia = {workspace = true }
 cftc_cot = {workspace = true }
 coffee_prices = {workspace = true }
 ice_stocks = {workspace = true }
-
 [tool.uv.workspace]
 members = [
     "extract/*",