feat(v5.2.0): finalize Infrastructure & Polish (tests isolation, xdist, lint, CI)

tests/conftest.py: mutate the settings singleton (instead of rebinding) so DB + backup dir are isolated per test -> pytest-xdist safe.
Real backup tests (snapshot/prune/admin API) and OAuth mock tests (Gitea/GitHub/link) replace the previous skips.
init_db() now also creates webhook_subscriptions (full schema without the FastAPI lifespan).
ruff check is clean; .eslintrc.json migrated to eslint.config.mjs (flat config).
CI: lint job (ruff + eslint), parallel tests (-n auto), run on every branch push.
VERSION 5.11.1.

app/routers/board.py

@@ -3,6 +3,7 @@ from __future__ import annotations
 
 import json
 import logging
+from pathlib import Path
 
 from fastapi import APIRouter, HTTPException, Query, Request
 from fastapi.responses import HTMLResponse, JSONResponse
@@ -150,20 +151,34 @@ def _file_icon(name: str, content_format: str = "") -> str:
     if content_format and content_format != 'file':
         return 'edit'
     n = name.lower()
-    if re.search(r'\.(png|jpe?g|gif|webp|svg|bmp|ico)$', n): return 'image'
-    if n.endswith('.pdf'): return 'file'
-    if re.search(r'\.(md|markdown)$', n): return 'edit'
-    if n.endswith('.py'): return 'file'
-    if re.search(r'\.(js|jsx|ts|tsx)$', n): return 'file'
-    if re.search(r'\.(html?|xml)$', n): return 'file'
-    if n.endswith('.css'): return 'file'
-    if n.endswith('.json'): return 'file'
-    if n.endswith('.sql'): return 'file'
-    if re.search(r'\.(sh|bash|zsh)$', n): return 'file'
-    if n.endswith('.ps1'): return 'file'
-    if re.search(r'\.(rs|go|java|rb|php|c|cpp|h|swift|kt|scala|r)$', n): return 'file'
-    if re.search(r'\.(txt|log)$', n): return 'file'
-    if re.search(r'\.(zip|tar|gz|rar|7z)$', n): return 'file'
+    if re.search(r'\.(png|jpe?g|gif|webp|svg|bmp|ico)$', n):
+        return 'image'
+    if n.endswith('.pdf'):
+        return 'file'
+    if re.search(r'\.(md|markdown)$', n):
+        return 'edit'
+    if n.endswith('.py'):
+        return 'file'
+    if re.search(r'\.(js|jsx|ts|tsx)$', n):
+        return 'file'
+    if re.search(r'\.(html?|xml)$', n):
+        return 'file'
+    if n.endswith('.css'):
+        return 'file'
+    if n.endswith('.json'):
+        return 'file'
+    if n.endswith('.sql'):
+        return 'file'
+    if re.search(r'\.(sh|bash|zsh)$', n):
+        return 'file'
+    if n.endswith('.ps1'):
+        return 'file'
+    if re.search(r'\.(rs|go|java|rb|php|c|cpp|h|swift|kt|scala|r)$', n):
+        return 'file'
+    if re.search(r'\.(txt|log)$', n):
+        return 'file'
+    if re.search(r'\.(zip|tar|gz|rar|7z)$', n):
+        return 'file'
     return 'file'
 
 
@@ -847,7 +862,7 @@ async def create_property(owner: str, repo: str, name: str = Query(...),
             )
             conn.commit()
         except Exception as e:
-            raise HTTPException(409, f"Property already exists: {e}")
+            raise HTTPException(409, f"Property already exists: {e}") from e
     return {"status": "ok", "name": name, "type": prop_type}
 
 
@@ -901,7 +916,7 @@ async def extract_ai_keywords(owner: str, repo: str):
             if not issue.get("pull_request"):
                 _extract_ai_keywords(owner, repo, issue.get("labels", []), issue.get("body", ""))
     except Exception as e:
-        raise HTTPException(500, str(e))
+        raise HTTPException(500, str(e)) from e
     return {"status": "ok", "issues_scanned": len(issues)}
 
 
@@ -980,7 +995,7 @@ async def save_page_blocks(request: Request, page_id: int):
     try:
         body = await request.json()
     except Exception:
-        raise HTTPException(400, "Invalid JSON body")
+        raise HTTPException(400, "Invalid JSON body") from None
     blocks_json = json.dumps(body.get("blocks", []))
     title = body.get("title", "")
     user = SessionManager.decode_session(request.cookies.get("flowdeck_session", ""))
@@ -1119,7 +1134,7 @@ async def restore_version(request: Request, page_id: int, version_id: int):
 @router.post("/api/pages/{page_id}/duplicate")
 async def duplicate_page(request: Request, page_id: int):
     """Duplicate a page (block/markdown content included) as a sibling."""
-    user = SessionManager.decode_session(request.cookies.get("flowdeck_session", ""))
+    SessionManager.decode_session(request.cookies.get("flowdeck_session", ""))
     with get_conn() as conn:
         row = conn.execute(
             "SELECT * FROM pages WHERE id=? AND deleted_at IS NULL", (page_id,)
@@ -1130,7 +1145,7 @@ async def duplicate_page(request: Request, page_id: int):
 
     def copy_tree(src_id: int, parent_id) -> int:
         with get_conn() as conn:
-            src = conn.execute("SELECT * FROM pages WHERE id=?", (src_id,)).fetchone()
+            conn.execute("SELECT * FROM pages WHERE id=?", (src_id,)).fetchone()
             cur = conn.execute(
                 "INSERT INTO pages (workspace, workspace_id, title, content, content_format, "
                 "parent_section, parent_id, sort_order, share_mode, published, is_published, "
@@ -1161,9 +1176,8 @@ async def duplicate_page(request: Request, page_id: int):
 # ═══════════ v5.5.0: Cover & icon ═══════════
 
 
-def _upload_root() -> "Path":
+def _upload_root() -> Path:
     import os
-    from pathlib import Path
     return Path(os.environ.get("FLOWDECK_DATA_DIR", "/data"))
 
 
@@ -1296,7 +1310,7 @@ async def import_page(request: Request):
     try:
         body = await request.json()
     except Exception:
-        raise HTTPException(400, "Invalid JSON body")
+        raise HTTPException(400, "Invalid JSON body") from None
     markdown = body.get("markdown", "")
     title = body.get("title", "")
     if not markdown and not body.get("csv"):
@@ -1328,7 +1342,7 @@ async def import_file(request: Request):
         try:
             zf = zipfile.ZipFile(_io.BytesIO(data))
         except zipfile.BadZipFile:
-            raise HTTPException(400, "Invalid zip archive")
+            raise HTTPException(400, "Invalid zip archive") from None
         md_entries = sorted(
             (n for n in zf.namelist() if n.lower().endswith((".md", ".markdown"))),
             key=lambda n: (n.count("/"), n.lower()),
@@ -1346,7 +1360,7 @@ async def import_file(request: Request):
         try:
             raw = data.decode("utf-8")
         except UnicodeDecodeError:
-            raise HTTPException(400, "Only text/markdown files are supported")
+            raise HTTPException(400, "Only text/markdown files are supported") from None
         title = filename.replace(".md", "").replace(".markdown", "").replace(".txt", "")
         created_ids.append(await _create_page_from_markdown(request, raw, title))
 
@@ -1361,7 +1375,7 @@ async def og_metadata(request: Request):
     try:
         body = await request.json()
     except Exception:
-        raise HTTPException(400, "Invalid JSON body")
+        raise HTTPException(400, "Invalid JSON body") from None
     url = (body.get("url") or "").strip()
     if not url:
         raise HTTPException(400, "url required")
@@ -1373,7 +1387,7 @@ async def og_metadata(request: Request):
 @router.put("/api/pages/{page_id}/move")
 async def move_page(request: Request, page_id: int):
     """Move a page to another workspace or reorder within tree.
-    
+
     Body (JSON): { workspace_id?: int, parent_id?: int, new_order?: int }
     - workspace_id: move page to a different workspace
     - parent_id: change parent (0 = root level)
@@ -1526,4 +1540,4 @@ async def sync_project(owner: str, repo: str):
                 conn.commit()
         return {"status": "ok", "issues_synced": len(issues_only)}
     except Exception as e:
-        raise HTTPException(500, str(e))
+        raise HTTPException(500, str(e)) from e