add devtools agent tools, fix search field mapping

7 gitea tools: list_repos, get_repo, list_issues, get_issue,
create_issue, list_pulls, get_file. all operate as the requesting
user via PAT impersonation.

tool registry conditionally includes gitea tools when configured.
dispatch uses prefix matching (gitea_*) for clean extension.

fixed search bug: room_name and sender_name filters used .keyword
subfield which doesn't exist on keyword-typed fields — queries
silently returned zero results for all room/sender-filtered searches.

src/tools/search.rs

@@ -38,10 +38,10 @@ pub fn build_search_query(args: &SearchArgs) -> serde_json::Value {
     })];
 
     if let Some(ref room) = args.room {
-        filter.push(json!({ "term": { "room_name.keyword": room } }));
+        filter.push(json!({ "term": { "room_name": room } }));
     }
     if let Some(ref sender) = args.sender {
-        filter.push(json!({ "term": { "sender_name.keyword": sender } }));
+        filter.push(json!({ "term": { "sender_name": sender } }));
     }
 
     let mut range = serde_json::Map::new();
@@ -189,7 +189,7 @@ mod tests {
 
         let filters = q["query"]["bool"]["filter"].as_array().unwrap();
         assert_eq!(filters.len(), 2);
-        assert_eq!(filters[1]["term"]["room_name.keyword"], "design");
+        assert_eq!(filters[1]["term"]["room_name"], "design");
     }
 
     #[test]
@@ -199,7 +199,7 @@ mod tests {
 
         let filters = q["query"]["bool"]["filter"].as_array().unwrap();
         assert_eq!(filters.len(), 2);
-        assert_eq!(filters[1]["term"]["sender_name.keyword"], "Bob");
+        assert_eq!(filters[1]["term"]["sender_name"], "Bob");
     }
 
     #[test]
@@ -209,8 +209,8 @@ mod tests {
 
         let filters = q["query"]["bool"]["filter"].as_array().unwrap();
         assert_eq!(filters.len(), 3);
-        assert_eq!(filters[1]["term"]["room_name.keyword"], "dev");
-        assert_eq!(filters[2]["term"]["sender_name.keyword"], "Carol");
+        assert_eq!(filters[1]["term"]["room_name"], "dev");
+        assert_eq!(filters[2]["term"]["sender_name"], "Carol");
     }
 
     #[test]
@@ -274,6 +274,30 @@ mod tests {
         assert_eq!(filters.len(), 1);
     }
 
+    #[test]
+    fn test_wildcard_query_uses_match_all() {
+        let args = parse_args(r#"{"query": "*"}"#);
+        let q = build_search_query(&args);
+        assert!(q["query"]["bool"]["must"][0]["match_all"].is_object());
+    }
+
+    #[test]
+    fn test_empty_query_uses_match_all() {
+        let args = parse_args(r#"{"query": ""}"#);
+        let q = build_search_query(&args);
+        assert!(q["query"]["bool"]["must"][0]["match_all"].is_object());
+    }
+
+    #[test]
+    fn test_room_filter_uses_keyword_field() {
+        // room_name is mapped as "keyword" in OpenSearch — no .keyword subfield
+        let args = parse_args(r#"{"query": "test", "room": "general"}"#);
+        let q = build_search_query(&args);
+        let filters = q["query"]["bool"]["filter"].as_array().unwrap();
+        // Should be room_name, NOT room_name.keyword
+        assert_eq!(filters[1]["term"]["room_name"], "general");
+    }
+
     #[test]
     fn test_source_fields() {
         let args = parse_args(r#"{"query": "test"}"#);