Add Stack Exchange ZIMs and wire Kiwix search into MCP server

- kiwix_download.sh: add Ask Ubuntu, Super User, Unix & Linux SE, Server Fault
- mcp_server.py: add kiwix_search tool — models can now query all offline ZIMs
- local-ai-setup.sh: pass KIWIX_URL env to MCP container, add kiwix dependency

https://claude.ai/code/session_012gDnantBmFTWZGCiKyjazx

mcp_server.py

@@ -16,6 +16,7 @@ GITEA_URL   = os.getenv("GITEA_URL",   "http://gitea:3000")
 GITEA_TOKEN = os.getenv("GITEA_TOKEN", "")
 GITHUB_TOKEN= os.getenv("GITHUB_TOKEN","")
 RAG_URL     = os.getenv("RAG_URL",     "http://rag-server:8001")
+KIWIX_URL   = os.getenv("KIWIX_URL",   "http://kiwix:80")
 
 mcp = FastMCP("local-dev-tools")
 
@@ -180,6 +181,27 @@ def github_api(method: str, endpoint: str, body: str = "") -> str:
     except Exception:
         return r.text
 
+# ── Kiwix search ──────────────────────────────────────────────────────────────
+import re as _re
+
+@mcp.tool()
+def kiwix_search(query: str, books: str = "") -> str:
+    """Search offline ZIM content via Kiwix (Wikipedia, Stack Overflow, etc).
+    books: optional comma-separated book names to filter, e.g. 'stackoverflow.com_en_all'.
+    Leave empty to search all ZIMs."""
+    params = {"pattern": query, "lang": ""}
+    if books:
+        params["books"] = books
+    try:
+        r = httpx.get(f"{KIWIX_URL}/search", params=params, timeout=15)
+        # strip HTML tags to get plain text
+        text = _re.sub(r"<[^>]+>", " ", r.text)
+        text = _re.sub(r"&[a-zA-Z]+;", " ", text)
+        text = _re.sub(r"\s{2,}", "\n", text).strip()
+        return text[:6000] or "(no results)"
+    except Exception as e:
+        return f"[kiwix error] {e}"
+
 # ── RAG ingest ────────────────────────────────────────────────────────────────
 @mcp.tool()
 def ingest_repo(url: str, name: str = "", branch: str = "main") -> str: