i18n: help-ai to help-astuces — 10 hardcoded texts now use data-i18n

- AI Editor: Complète, flashe en vert, Ton décontracté
- Webhooks: notify, POST HTTP, blog post, note événement
- Tips: Utilisez les tags, sidebar, filtrage
- Added 10 new keys to en.json/fr.json (1046 -> 1056)

frontend/locales/en.json

@@ -143,7 +143,7 @@
   "ai.to_canvas": "Convert to Canvas",
   "ai.custom_rewrite": "Custom rewrite",
   "ai.no_api_key": "No API key configured",
-  "ai.select_text": "Select text to process",
+  "ai.select_text": "AI: select text to process",
   "ai.done": "AI: text processed",
   "ai.completion_added": "AI: completion added",
   "ai.rewrite_done": "AI: text rewritten",
@@ -985,11 +985,9 @@
   "help.graph_info": "Info panel",
   "help.graph_export": "Export PNG",
   "help.graph_context": "Context menu",
-  "ai.completion_added": "AI: completion added",
   "ai.invalid_api_key": "AI: invalid API key. Check DEEPSEEK_API_KEY in .env",
   "ai.processing": "⏳ AI: processing...",
   "ai.quota_exceeded": "AI: quota exceeded or payment required",
-  "ai.select_text": "AI: select text to process",
   "ai.text_processed": "AI: text processed ✓",
   "ai.text_rewritten": "AI: text rewritten",
   "auth.cannot_delete_self": "Cannot delete your own account",
@@ -1044,15 +1042,20 @@
   "help.shortcut_command_palette": "Command palette",
   "help.shortcut_quick_search": "Quick search (outside text field)",
   "help.shortcut_close_editor": "Close editor / modal",
-  "help.shortcut_forge_help": "Forge editor help",
   "help.shortcut_file_palette": "File palette (quick nav.)",
   "help.shortcut_save_file": "Save open file",
   "help.shortcut_ai_completion": "Inline AI completion (in editor)",
-  "help.shortcut_focus_search": "Focus search bar",
   "help.shortcut_search_doc": "Search in document",
   "help.shortcut_quick_insert": "Quick insert (Forge editor)",
   "help.shortcut_tip": "Hover over a document with <strong>Ctrl</strong> for a quick preview. Click <strong>Forge</strong> in the toolbar for the advanced editor.",
-  "dashboard.tab_stats": "Statistics",
-  "dashboard.tab_recent": "Recent",
-  "dashboard.tab_shared": "Shared"
+  "help.ai_completes": "Completes",
+  "help.ai_flash_green": "flashes green",
+  "help.ai_tone_casual": "Casual tone",
+  "help.webhook_notify": "automatically notify services",
+  "help.webhook_post": "HTTP POST to your",
+  "help.webhook_blog_post": "blog post when a file is marked",
+  "help.webhook_note": "Note: the event",
+  "help.tip_use_tags": "Use tags",
+  "help.tip_hide_sidebar": "Hide the sidebar",
+  "help.tip_sidebar_filter": "Use sidebar filtering"
 }