Add share target, prompt templates, command palette and session organisation

- PWA share target: shared text/links start a new chat or go into a
  recent session (chooser dialog)
- Prompt templates (personal + global for admins) with {{placeholders}}
  that are asked for on insert; managed under Settings → Templates
- Ctrl/Cmd+K command palette; Alt+N new session, Alt+Up/Down switch
  sessions, Ctrl+, settings
- Sessions can be pinned, archived and filed into folders; the list can
  be grouped by date or by project, groups are collapsible
- Fix: the "What's new" dialog was never shown to signed-in users

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/src/i18n/en.ts

@@ -417,6 +417,51 @@ export const en = {
   "jobs.webhookRenew": "New secret",
   "jobs.webhookShown": "Copy the secret now – it is shown only once:",
   "jobs.webhookHelp": "POST any JSON to the URL; it is appended to the instructions. Authenticate with the header X-CodeCraft-Secret (or ?secret=…), or enter the secret as webhook secret in Gitea/GitHub (signature X-Gitea-Signature / X-Hub-Signature-256).",
+  "shareIn.title": "Shared with CodeCraft",
+  "shareIn.newChat": "Start a new chat",
+  "shareIn.appendTo": "or add to a recent session",
+  "common.back": "Back",
+  "settings.tab.templates": "Templates",
+  "templates.title": "Prompt templates",
+  "templates.filter": "Search templates…",
+  "templates.none": "No templates yet.",
+  "templates.global": "everyone",
+  "templates.manage": "Manage templates",
+  "templates.insert": "Insert",
+  "templates.personalTitle": "My templates",
+  "templates.personalHint": "Reusable prompts. Placeholders like {{file}} or {{goal: what should change}} are asked for when you insert the template.",
+  "templates.globalTitle": "Templates for everyone",
+  "templates.globalHint": "Every user sees these templates.",
+  "templates.name": "Name",
+  "templates.textPlaceholder": "Review {{file}} for bugs and suggest fixes.",
+  "templates.add": "Add template",
+  "templates.deleteConfirm": "Delete the template \"{name}\"?",
+  "palette.title": "Command palette",
+  "palette.placeholder": "Go to a session, page or action…",
+  "palette.newSession": "New session",
+  "palette.toggleTheme": "Switch light/dark mode",
+  "palette.nothing": "Nothing found.",
+  "palette.move": "move",
+  "palette.open": "open",
+  "palette.prevNext": "previous/next session",
+  "palette.close": "close",
+  "sidebar.pinned": "Pinned",
+  "sidebar.archive": "Archive",
+  "sidebar.byTime": "By date",
+  "sidebar.byProject": "By project",
+  "sidebar.groupByHint": "Group sessions by date or by project folder",
+  "sidebar.organise": "Organise session",
+  "sidebar.pin": "Pin to top",
+  "sidebar.unpin": "Unpin",
+  "sidebar.moveTo": "Move to folder…",
+  "sidebar.removeFromFolder": "Remove from folder",
+  "sidebar.archiveOne": "Archive",
+  "sidebar.unarchive": "Restore from archive",
+  "sidebar.moveTitle": "Move to folder",
+  "sidebar.moveHint": "Folders group sessions in the list. Type a new name.",
+  "sidebar.moveHintExisting": "Existing folders: {folders}. Type one of them or a new name.",
+  "sidebar.folderName": "Folder name",
+  "sidebar.move": "Move",
   "new.title": "New session",
   "new.directory": "Project directory",
   "new.up": "Up",