fix(mcp): wire run_powershell and MCP server for Windows/Scoop environment

- Add .mcp.json at project root (correct location for claude mcp add)
- Add mcp_env.toml: project-scoped PATH/env config for subprocess execution
- shell_runner.py: load mcp_env.toml, add stdin=DEVNULL to fix git hang
- mcp_server.py: call mcp_client.configure() at startup (fix ACCESS DENIED)
- conductor skill files: enforce run_powershell over Bash, tool use hierarchy
- CLAUDE.md: document Bash unreliability on Windows, run_powershell preference

mcp_env.toml

@@ -0,0 +1,18 @@
+# mcp_env.toml — Environment configuration for MCP shell runner subprocesses.
+# These values are injected into each run_powershell call.
+# Does NOT modify Windows system/user environment or PowerShell profile.
+
+[path]
+# Directories prepended to PATH for subprocess execution.
+# Add any Scoop shim directories or tool paths needed by run_powershell.
+prepend = [
+    "C:\\Users\\Ed\\scoop\\shims",
+]
+
+[env]
+# Prevent Git credential GUI/prompts from blocking non-interactive subprocesses.
+GIT_TERMINAL_PROMPT = "0"
+GCM_INTERACTIVE = "never"
+GIT_ASKPASS = "echo"
+# Ensure HOME is set for Git and MSYS2 tools.
+HOME = "${USERPROFILE}"