feat: Domain 2 Phase 3-4 — wiki article tool, DCP compress toggle, Go sidecar deprecation

Phase 3: get_wiki_article tool wraps codesight_get_wiki_article MCP
(cached, persistent codebase wiki). DCP compress toggle on
get_codebase_overview (compress=true for large projects >50 files).

Phase 4: Deprecation markers on Go codecontext sidecar. Warning log
in callCodecontext(), deprecation comments in factory.ts and
docker-compose.yml. Sidecar remains functional — removal deferred.

codecontext/README.md

@@ -0,0 +1,31 @@
+# codecontext — Go sidecar (DEPRECATED)
+
+> **Deprecated** (Phase 4, Domain 2, v2.8.14).
+>
+> Superseded by the **boocontext MCP server** (`apps/coder`). Do not add new
+> callers. The 16 codecontext tool wrappers still use this sidecar via HTTP at
+> `http://codecontext:8080/v1/{toolName}` for backward compatibility.
+
+## Migration path
+
+1. Existing tool wrappers in `apps/server/src/services/tools/codecontext/` route
+   through `callCodecontext()` in `codecontext_client.ts`, which calls this
+   Go sidecar over HTTP.
+2. New callers should use the boocontext MCP server instead (reachable via the
+   `boocontext` tool wrappers).
+3. After all callers have migrated, remove this directory, the `codecontext`
+   service block from `docker-compose.yml`, and the
+   `codecontext_client.ts`/`factory.ts` files.
+
+## What it does
+
+A Go HTTP shim wrapping the boocontext MCP server's stdio interface. Provides
+code-graph analysis (symbols, callers, callees, file overview, etc.) over a
+REST API at `/v1/{toolName}`.
+
+## Files
+
+- `shim.go` — HTTP server that wraps the boocontext MCP stdio process
+- `Dockerfile` — container build
+- `fork.tar.gz` — vendored boocontext source (gitignored)
+- `.codecontextignore.template` — default ignore patterns deployed per project