feat(wiki,templates): v5.11.0 wiki-links & mentions + v5.12.0 templates & page lock (release 5.12.0)

v5.11.0 Wiki-links & mentions de page :
- tokens [[fdpage:ID]] / [[fddate:ISO]] dans le texte des blocs,
  service app/services/wiki_links.py (labels, rendu HTML, extraction)
- taper [[ ouvre le picker de pages (recherche floue, clavier) ;
  le menu @ gagne les sections Pages et Date (today/tomorrow/YYYY-MM-DD)
- chips atomiques contenteditable=false relues en tokens par gtTok()
  (autosave/drag/undo preservent les liens) ; renommage propage via
  GET /board/api/wiki/titles ; backlinks reconnaissent les tokens ;
  page publique rend les chips (echopee)

v5.12.0 Templates & verrouillage :
- template picker global sur + New page : 5 built-in
  (app/services/block_templates.py) + templates perso
  (table page_global_templates, migration 13)
- POST /board/api/page-templates (save current page) + /{id}/use
  (instantiate, id 0 = built-in par cle)
- page lock : POST /api/pages/{id}/lock, garde _ensure_page_editable
  -> 423 en ecriture pour les non-privileged, deblocage par
  locked_by ou admin seulement (403 sinon), banniere + read-only UI
- full-width / small text par page (pages.full_width/font_small,
  POST /api/pages/{id}/options, classes CSS)
- migration 13 : is_locked, locked_by, full_width, font_small,
  page_global_templates

Tests : tests/test_v511_v512_wiki_templates.py (15) ; suite complete
538 verte ; ruff OK ; node --check des templates JS OK.

app/main.py

@@ -92,7 +92,7 @@ async def lifespan(_app: FastAPI):
     from app.services.reminders import reminder_scheduler
     reminder_task = asyncio.create_task(reminder_scheduler())
 
-    logger.info("FlowDeck v5.11.7 started on port %d", settings.app_port)
+    logger.info("FlowDeck v5.12.0 started on port %d", settings.app_port)
     try:
         yield
     finally:
@@ -107,7 +107,7 @@ async def lifespan(_app: FastAPI):
 
 app = FastAPI(
     title="FlowDeck",
-    version="5.11.7",
+    version="5.12.0",
     docs_url="/docs" if settings.log_level == "DEBUG" else None,
     redoc_url=None,
     lifespan=lifespan,