feat: add output truncation and offset paging to all large-output tools

- coding_tools: list_files (max_entries=200, sorted), run_command
  (max_chars=8000, output_offset), grep_search (max_lines=100, offset);
  added _truncate_output helper for run_command paging
- pr_tools: get_pull_request_diff / get_pull_request_patch now truncate
  at 15k chars with hunk-boundary awareness and char_offset paging;
  get_pull_request_comments gains limit/offset paging
- issue_tools: get_issue_comments gains limit/offset paging
- file_tools: get_file_content / get_file_content_with_ref now paginate
  by line (offset=1, limit=250), matching existing read_file convention;
  added _paginate_lines helper
- research_tools: fetch_url gains char_offset parameter; _smart_truncate
  now slices from an offset and embeds next char_offset in the footer
- gitea_tools facade: all new params threaded through

gitea/tools/gitea_tools.py

@@ -33,13 +33,27 @@ class GiteaTools:
         """Close a pull request. Args: owner (repo owner), repo (repo name), pull_number (PR ID)."""
         return self.pr_tools.close_pull_request(owner, repo, pull_number)
 
-    def get_issue_comments(self, owner: str, repo: str, issue_number: int) -> str:
-        """Get all comments on an issue. Args: owner (repo owner), repo (repo name), issue_number (issue ID)."""
-        return self.issue_tools.get_issue_comments(owner, repo, issue_number)
+    def get_issue_comments(
+        self,
+        owner: str,
+        repo: str,
+        issue_number: int,
+        limit: int = 20,
+        offset: int = 0,
+    ) -> str:
+        """Get all comments on an issue. Args: owner, repo, issue_number, limit (default 20), offset (default 0)."""
+        return self.issue_tools.get_issue_comments(owner, repo, issue_number, limit=limit, offset=offset)
 
-    def get_pull_request_comments(self, owner: str, repo: str, pull_number: int) -> str:
-        """Get all comments on a pull request. Args: owner (repo owner), repo (repo name), pull_number (PR ID)."""
-        return self.pr_tools.get_pull_request_comments(owner, repo, pull_number)
+    def get_pull_request_comments(
+        self,
+        owner: str,
+        repo: str,
+        pull_number: int,
+        limit: int = 20,
+        offset: int = 0,
+    ) -> str:
+        """Get all comments on a pull request. Args: owner, repo, pull_number, limit (default 20), offset (default 0)."""
+        return self.pr_tools.get_pull_request_comments(owner, repo, pull_number, limit=limit, offset=offset)
 
     def list_assigned_issues(self) -> list[dict]:
         """List all issues assigned to the authenticated user across all repos."""
@@ -57,9 +71,16 @@ class GiteaTools:
         """List pull requests in a repository. Args: owner (repo owner), repo (repo name), state (open, closed, or all)."""
         return self.pr_tools.list_pull_requests(owner, repo, state)
 
-    def get_file_content(self, owner: str, repo: str, path: str) -> str:
-        """Get the content of a file from a repository. Args: owner (repo owner), repo (repo name), path (file path)."""
-        return self.file_tools.get_file_content(owner, repo, path)
+    def get_file_content(
+        self,
+        owner: str,
+        repo: str,
+        path: str,
+        offset: int = 1,
+        limit: int = 250,
+    ) -> str:
+        """Get the content of a file from a repository. Args: owner, repo, path, offset (line, default 1), limit (default 250)."""
+        return self.file_tools.get_file_content(owner, repo, path, offset=offset, limit=limit)
 
     def create_pull_request(self, owner: str, repo: str, head: str, base: str, title: str, description: str = "") -> str:
         """Create a new pull request. Args: owner, repo, head (source branch), base (target branch), title, description."""
@@ -89,13 +110,27 @@ class GiteaTools:
         """Add a comment to an issue. Args: owner, repo, issue_number, body."""
         return self.issue_tools.add_comment_to_issue(owner, repo, issue_number, body)
 
-    def get_pull_request_diff(self, owner: str, repo: str, pull_number: int) -> str:
-        """Get the diff of a pull request. Args: owner, repo, pull_number."""
-        return self.pr_tools.get_pull_request_diff(owner, repo, pull_number)
+    def get_pull_request_diff(
+        self,
+        owner: str,
+        repo: str,
+        pull_number: int,
+        max_chars: int = 15000,
+        char_offset: int = 0,
+    ) -> str:
+        """Get the diff of a pull request. Args: owner, repo, pull_number, max_chars (default 15000), char_offset (default 0)."""
+        return self.pr_tools.get_pull_request_diff(owner, repo, pull_number, max_chars=max_chars, char_offset=char_offset)
 
-    def get_pull_request_patch(self, owner: str, repo: str, pull_number: int) -> str:
-        """Get the patch of a pull request. Args: owner, repo, pull_number."""
-        return self.pr_tools.get_pull_request_patch(owner, repo, pull_number)
+    def get_pull_request_patch(
+        self,
+        owner: str,
+        repo: str,
+        pull_number: int,
+        max_chars: int = 15000,
+        char_offset: int = 0,
+    ) -> str:
+        """Get the patch of a pull request. Args: owner, repo, pull_number, max_chars (default 15000), char_offset (default 0)."""
+        return self.pr_tools.get_pull_request_patch(owner, repo, pull_number, max_chars=max_chars, char_offset=char_offset)
 
     def approve_pull_request(self, owner: str, repo: str, pull_number: int, comment: str) -> str:
         """Approve a pull request. Args: owner, repo, pull_number, comment."""
@@ -113,9 +148,17 @@ class GiteaTools:
         """Add a label to an issue. Args: owner, repo, issue_number, label."""
         return self.issue_tools.add_label(owner, repo, issue_number, label)
 
-    def get_file_content_with_ref(self, owner: str, repo: str, path: str, ref: str = "master") -> str:
-        """Get file content with a specific git ref. Args: owner, repo, path, ref (branch/tag)."""
-        return self.file_tools.get_file_content_with_ref(owner, repo, path, ref)
+    def get_file_content_with_ref(
+        self,
+        owner: str,
+        repo: str,
+        path: str,
+        ref: str = "master",
+        offset: int = 1,
+        limit: int = 250,
+    ) -> str:
+        """Get file content with a specific git ref. Args: owner, repo, path, ref (branch/tag), offset (line, default 1), limit (default 250)."""
+        return self.file_tools.get_file_content_with_ref(owner, repo, path, ref=ref, offset=offset, limit=limit)
 
     def update_file(self, owner: str, repo: str, path: str, message: str, content: str, branch: str) -> str:
         """Update a file in a repository. Args: owner, repo, path, message, content, branch."""