refactor(registry): move MCP servers from code to JSON manifests (#1144)

* refactor(registry): move MCP server entries from code to JSON manifests

Move 8 hardcoded MCP server RegistryEntry structs from
builtin_entries() into data-driven JSON files under
registry/mcp-servers/, matching the existing pattern used by
tools and channels. Exclude the GitHub MCP entry which conflicts
with the WASM GitHub tool's OAuth flow.

Extend ManifestKind with McpServer, make version/source optional
on ExtensionManifest (MCP servers don't need them), and add
url/auth fields for MCP-specific config. Update build.rs,
embedded catalog, catalog loader, installer, and CLI display
to handle the new kind and optional fields.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

* fix(registry): address PR review — add missing slack-mcp, remove .expect(), fix fmt

- Add missing slack-mcp.json (was dropped during migration)
- Remove production .expect() in get_strict(), replace with .ok_or_else()
- Clean up unwrap_or_default() in key_for() to use .next() directly
- Log warning for MCP manifests missing url field instead of silent empty
- Run cargo fmt to fix formatting diffs

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

* ci: re-trigger CI with correct base branch (staging)

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

* fix(ci): improve no-panics check to properly exclude test modules

The grep-based filter only excluded lines literally containing
#[cfg(test)], #[test], or 'mod tests' — not lines *inside* test
modules. Use awk to track hunk context from diff @@ headers and
skip all added lines within test module hunks.

[skip-regression-check]

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

* refactor(registry): remove slack-mcp MCP entry (conflicts with WASM slack tool)

Remove slack-mcp.json alongside the already-excluded github MCP
entry — both conflict with existing WASM tools of the same name.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

* fix(registry): address re-review — skip invalid MCP entries, fix install order

- to_registry_entry() now returns Option<RegistryEntry>; MCP manifests
  missing a url field are skipped with a warning instead of creating
  broken entries with empty URLs
- Move McpServer early-return before require_source() in install paths
  so the error message is clear ("cannot install MCP servers") rather
  than the misleading "missing source spec"
- Add test for MCP manifest with missing URL returning None

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <[email protected]>

.github/workflows/code_style.yml

@@ -89,19 +89,34 @@ jobs:
     - name: Check for .unwrap(), .expect(), assert!() in production code
       run: |
         BASE="${{ github.event.pull_request.base.sha }}"
-        # Get added lines in .rs files (production only, exclude tests/)
-        ADDED=$(git diff "$BASE"...HEAD -- 'src/**/*.rs' 'crates/**/*.rs' \
-          | grep -E '^\+[^+]' || true)
+        # Get the full diff for .rs files (production only, exclude tests/ directory)
+        DIFF=$(git diff "$BASE"...HEAD -- 'src/**/*.rs' 'crates/**/*.rs' || true)
 
-        if [ -z "$ADDED" ]; then
+        if [ -z "$DIFF" ]; then
           echo "No production Rust changes detected."
           exit 0
         fi
 
-        # Match panic-inducing patterns, excluding test code and safety suppressions
+        # Extract added lines, skipping those inside test modules.
+        # Track whether we're inside a test module by watching hunk headers
+        # (lines starting with @@) whose context contains "mod tests" or "#[cfg(test)]".
+        ADDED=$(echo "$DIFF" | awk '
+          /^@@/ {
+            # Hunk context (after the second @@) tells us the function/module scope
+            in_test = (tolower($0) ~ /mod tests/ || $0 ~ /#\[cfg\(test\)\]/ || $0 ~ /#\[test\]/)
+          }
+          /^\+[^+]/ && !in_test { print }
+        ' || true)
+
+        if [ -z "$ADDED" ]; then
+          echo "No production Rust changes detected (test-only changes excluded)."
+          exit 0
+        fi
+
+        # Match panic-inducing patterns, excluding safety suppressions
         VIOLATIONS=$(echo "$ADDED" \
           | grep -E '\.(unwrap|expect)\(|[^_]assert(_eq|_ne)?!' \
-          | grep -Ev 'debug_assert|// safety:|#\[cfg\(test\)\]|#\[test\]|mod tests' \
+          | grep -Ev 'debug_assert|// safety:' \
           || true)
 
         if [ -n "$VIOLATIONS" ]; then