feat: #61 Plugin system — backend API, sandboxed Web Worker, hooks wired to real app flow, user guide, 47+21 tests

frontend/locales/en.json

@@ -460,6 +460,7 @@
   "config.section_watcher": "Auto sync",
   "config.section_webhooks": "🔗 Webhooks",
   "config.section_push": "🔔 Push notifications",
+  "config.section_plugins": "🧩 Plugins",
   "config.section_workflow-recommande": "Recommended workflow",
   "config.section_zone-de-contenu": "Zone de contenu",
   "config.server_config": "Server config",
@@ -486,6 +487,8 @@
   "config.webhook_url_placeholder": "URL",
   "config.webhooks": "Webhooks",
   "config.webhooks_desc": "HTTP notifications to external services on file changes.",
+  "config.plugins": "Plugins",
+  "config.plugins_desc": "Manage installed plugins for this vault.",
   "config.workers_label": "Search workers",
   "confirm.delete_dir": "Delete this folder and all its contents?",
   "confirm.delete_dir_named": "Delete \"{path}\" and ALL its contents?",
@@ -1072,6 +1075,7 @@
   "help.nav_tags": "🏷️ Tags",
   "help.nav_tips": "💡 Tips",
   "help.nav_webhooks": "🪝 Webhooks",
+  "help.nav_plugins": "🧩 Plugins",
   "help.new_file": "New file",
   "help.new_folder": "New folder",
   "help.nights": "sleepless nights 😅",
@@ -1338,6 +1342,7 @@
   "settings.search_placeholder": "Search...",
   "settings.sync": "🔄 Sync",
   "settings.themes": "🎨 Themes",
+  "settings.plugins": "🧩 Plugins",
   "share.copied": "Link copied!",
   "share.copy_link": "Copy link",
   "share.create": "Create share link",
@@ -1614,5 +1619,30 @@
   "mfa.webauthn_prompt": "Present your security key or confirm with Windows Hello.",
   "mfa.webauthn_btn": "Verify with my key",
   "mfa.webauthn_cancelled": "WebAuthn ceremony cancelled.",
-  "mfa.webauthn_no_key": "No security key registered for this account."
-}
+  "mfa.webauthn_no_key": "No security key registered for this account.",
+  "plugins.title": "🧩 Plugins",
+  "plugins.description": "Extend ObsiGate with custom renderers, search filters, and editor actions.",
+  "plugins.install": "Install Plugin",
+  "plugins.template": "View Template",
+  "plugins.none": "No plugins installed.",
+  "plugins.manifest_json": "Manifest (plugin.json)",
+  "plugins.code": "Plugin Code (main file)",
+  "plugins.view_code": "View Code",
+  "plugins.uninstall": "Uninstall",
+  "plugins.enable": "Enable",
+  "plugins.disable": "Disable",
+  "plugins.enabled": "Plugin '{name}' enabled.",
+  "plugins.disabled": "Plugin '{name}' disabled.",
+  "plugins.installed": "Plugin '{name}' installed successfully.",
+  "plugins.uninstalled": "Plugin '{name}' uninstalled.",
+  "plugins.confirm_uninstall": "Uninstall plugin '{name}'? This cannot be undone.",
+  "help.plugins_title": "🧩 Plugins",
+  "help.plugins_intro": "ObsiGate supports a plugin system to extend its functionality. Plugins can add custom renderers, search filters, editor actions, and UI elements.",
+  "help.plugins_install": "Installation",
+  "help.plugins_manage": "Management",
+  "help.plugins_develop": "Development",
+  "help.plugins_dev_intro": "A plugin is a folder or ZIP containing:",
+  "help.plugins_hooks_desc": "Available hooks: <code>onFileRender</code>, <code>onSearchFilter</code>, <code>onEditorAction</code>, <code>onSidebarItem</code>, <code>onFileCreate</code>, <code>onFileDelete</code>, <code>onVaultMount</code>.",
+  "help.plugins_security": "<strong>Security:</strong> each plugin runs in an isolated Web Worker sandbox, with no DOM, localStorage, or network access unless explicitly granted via permissions.",
+  "help.plugins_template": "Use the <strong>Template</strong> button in Settings > Plugins to generate a valid starter plugin."
+}