feat(import): v5.6.0 unified data import (phases 0-5)

- unified importer framework (app/services/importers/): normalized model,
  registry, common pipeline (hierarchy, attachments, collections, dedup),
  async jobs, dry-run preview, column->type mapping
- Phase 1: Obsidian, Notion, Logseq/Roam, HTML (Apple Notes/Bear/Ulysses/
  OneNote), Google Keep, generic Markdown
- Phase 2: typed CSV/TSV, Excel (openpyxl), generic JSON
- Phase 3: Word .docx (python-docx), PDF (pypdf), HTML folders
- Phase 4: Raindrop, Pocket, Readwise, Shaarli, Netscape bookmarks, .ics,
  OPML, Standard Notes, Gitea/GitHub issues (+labels/milestones)
- Phase 5: incremental re-sync (skip/update/duplicate), partial-error resume,
  forge repo files, URL web clipper (SSRF guard), batch multi-file + UI queue,
  Notion relation resolution, exportable JSON reports
- /import wizard, API /api/import/*, migration 9 (import_items, import_jobs)
- fix: property values stored by property id (correct DB view rendering)
- deps: openpyxl, beautifulsoup4, PyYAML, python-docx, pypdf
- 43 import tests; full suite 491 green; ruff clean
- bump version 5.11.5

app/services/github_adapter.py

@@ -209,6 +209,60 @@ class GitHubAdapter(ForgeAdapter):
             resp.raise_for_status()
             return resp.json()
 
+    # ── issues / labels / milestones ──
+
+    async def list_issues(self, owner: str, repo: str, state: str = "all") -> list[dict]:
+        """List issues (pull requests are filtered out)."""
+        issues: list[dict] = []
+        for page in range(1, 6):
+            async with self._client() as client:
+                resp = await client.get(
+                    f"{self._base}/repos/{owner}/{repo}/issues",
+                    headers=self._headers,
+                    params={"state": state, "per_page": 100, "page": page},
+                )
+                resp.raise_for_status()
+                batch = resp.json()
+            if not batch:
+                break
+            issues.extend(i for i in batch if "pull_request" not in i)
+            if len(batch) < 100:
+                break
+        return issues
+
+    async def list_labels(self, owner: str, repo: str) -> list[dict]:
+        async with self._client() as client:
+            resp = await client.get(
+                f"{self._base}/repos/{owner}/{repo}/labels",
+                headers=self._headers,
+                params={"per_page": 100},
+            )
+            resp.raise_for_status()
+            return resp.json()
+
+    async def list_milestones(self, owner: str, repo: str, state: str = "all") -> list[dict]:
+        async with self._client() as client:
+            resp = await client.get(
+                f"{self._base}/repos/{owner}/{repo}/milestones",
+                headers=self._headers,
+                params={"state": state, "per_page": 100},
+            )
+            resp.raise_for_status()
+            return resp.json()
+
+    async def list_repo_files(self, owner: str, repo: str, path: str = "") -> list[dict]:
+        """Flatten the repo tree into file entries (``path``, ``size``)."""
+        tree = await self.get_repo_tree(owner, repo)
+        prefix = path.strip("/")
+        files = [
+            {"path": item["path"], "size": item.get("size", 0)}
+            for item in tree
+            if item.get("type") == "blob" and item.get("path")
+        ]
+        if prefix:
+            files = [f for f in files if f["path"].startswith(prefix + "/") or f["path"] == prefix]
+        return files
+
     # ── token validation ──
 
     async def validate_token(self) -> bool: