feat(plugins): plugin pages, per-user config, capabilities gate, mobile/telegram refactors

- Plugin HTTP routes + web pages (plugin-page-host, plugin-catalog, plugin-detail)
- Plugin access grants + per-user config (DB tables + API + frontend forms)
- Capabilities-based guard (caps.rs) replacing role-id checks
- Mobile connector: message routing, payload types, router refactor
- Telegram bot: auth flow, event handling improvements
- Honcho plugin: substantial rework
- Sidebar: plugin pages integration, role-driven visibility
- i18n: new strings for plugins, connectors, capabilities
- Remove unused mascot asset

CLAUDE.md

@@ -55,6 +55,10 @@ Two rules keep the boundary real, and both are enforced by the compiler:
 - **The core never names a plugin.** A plugin contributes tools through `Plugin::tools(self: Arc<Self>)` — the sibling of `http_router()` — so nothing in the core has to downcast to a concrete type. Naming one would drag every plugin in the tree into the core, including a C build via `plugin-transcribe-whisper-local`.
 - **The core never learns about the process shell.** The `restart` tool defaults to the supervisor protocol (`exit(-1)`); a shell with different needs installs `tools::restart::set_restart_handler` at startup. The Tauri shell installs teardown-and-respawn there. This is why `skald-core` has no `desktop` feature.
 
+**Plugin visibility & per-user config.** Plugins are managed from the `#plugins` page, not only by the agent. Enable/disable + instance config + access grants are gated by the `plugin.manage` capability (admin-only by construction). Visibility is **opt-in**: a row in `plugin_access(plugin_id, user_id)` grants a user sight of an enabled plugin (`plugin_id` is bare TEXT, never a FK — a `plugins` row exists only after the first toggle). A plugin with a non-empty `Plugin::user_config_schema()` exposes per-user settings, stored in `plugin_user_configs` (**admin-readable system.db — never secrets**) and applied through the `Plugin::update_user_config` hook, whose default just stores the blob via the `PluginUserConfigApi` on `PluginContext.user_config`. Telegram is the reference impl: the user pastes the bot's pairing code in their Plugins page, the override turns it into a `chat_id → user_id` binding (same write path as the `telegram_pairing` tool) and stores a `{linked, chat_id}` status blob for the UI. Endpoints: admin `GET/PUT /api/plugins[/{id}]` + `GET/PUT /api/plugins/{id}/access`; user `GET /api/plugins/mine` + `PUT /api/plugins/{id}/my-config`.
+
+**Plugin HTTP routes & web pages.** Every plugin's `http_router()` mounts at boot under `/api/plugin/<id>/` — **enabled or not**: two shared gates wrap each router (`require_auth`, then `guard::plugin_enabled_gate`, which re-checks the DB flag per request and answers 404 while disabled), so enable/disable serves/stops routes immediately with no restart, and plugin responses carry `Cache-Control: no-cache`. The router contract: cheap and safe to build pre-start, handlers tolerant of the not-running state (resolve runtime state per request through a shared cell, as mobile-connector does). A plugin may also contribute **frontend pages** via `Plugin::web_pages()` (`PluginPage { page_id, title, icon, entry, admin_only, priority }`): `GET /api/plugins/pages` returns the caller's visible pages (admin: all; others: non-`admin_only` pages of granted, enabled plugins) with `entry_url` resolved, and the sidebar renders them as menu entries routed `#plugin/<plugin_id>/<page_id>`. A single `<plugin-page-host>` (`web/components/plugin-page-host.js`) dynamic-imports the fragment ES module the plugin serves from its own router, registers its default-exported HTMLElement class, and mounts it with the `plugin-id` attribute — the fragment talks to its backend only through `/api/plugin/<id>/…` and runs with full session privileges (plugins are trusted: they ship in the binary). The frontend knows nothing about plugin page contents or behavior.
+
 `skald_core::boot` emits curated startup lines on the `boot` tracing target; each shell decides how to render them (`src/boot_format.rs` here). The core says what happened, never how it looks.
 
 ## Key modules
@@ -78,7 +82,7 @@ Two rules keep the boundary real, and both are enforced by the compiler:
 | `crates/skald-core/src/crypto/` | Envelope encryption (§4/§5.1). A random 256-bit DEK encrypts `{userid}.db`; `users.database_password` holds it sealed with AES-256-GCM under `Argon2id(password, salt)`. **The AEAD tag is the password verifier** — one derivation both authenticates and yields the key, and no second hash sits in the admin-readable DB. Cleartext users store the Argon2id output directly, compared constant-time. Argon2 runs in `spawn_blocking` behind a 2-permit semaphore (256 MiB per derivation) |
 | `src/config.rs` | Loads `config.yml`; LLM clients, strength/use_cases, data root. Also hosts `bootstrap_data_dir()` — under the `desktop` feature, relocates the process cwd to a per-user data dir when running inside a `.app` bundle (no-op in dev mode and headless mode) |
 | `crates/skald-core/src/mcp/` | MCP runtimes + the `McpProvider` seam (§7): the shared host **global** runtime and the per-user **container** runtimes, unioned per session as `UserMcpView`. See the MCP connectors section |
-| `crates/skald-core/src/plugin/` | Plugin system: discovery, enable/disable, tool registration |
+| `crates/skald-core/src/plugin/` | Plugin system: discovery, enable/disable, tool registration, per-user access grants + per-user config |
 | `crates/skald-core/src/cron/` | Scheduled job runner |
 | `crates/skald-core/src/compactor.rs` | Context compaction (summarises history when token budget exceeded) |
 | `crates/skald-core/src/approval/` | Approval rules engine |
@@ -100,7 +104,7 @@ Two rules keep the boundary real, and both are enforced by the compiler:
 
 The schema is split into two buckets (§5.1), and the split is the point:
 
-- **`create_registry_tables`** — instance-wide, readable without any user key: `users`, `roles`, `llm_providers`, `llm_models`, `transcribe_models`, `tts_models`, `image_generate_models`, `plugins`, `approval_rules`, `tool_permission_groups`, `config`, `known_tools`, `llm_requests`, `mcp_catalog`, `mcp_global_servers` + `mcp_global_access`, `oauth_providers`, `role_capabilities`, `shared_folders` + `shared_folder_members`. The MCP tables back the Connectors model (§7/§14/§15 — see its own section); `oauth_providers` (accessor `db/oauth_providers.rs`) holds one row per identity provider (Google…) — endpoints + `client_id`/`client_secret` + `redirect_uri`, admin-owned household secrets (§4/§15b), never a per-user token. The last two (accessor `db/shared_folders.rs`) are the **membership** of the on-disk shared folders (§6): a junction table so a member can be read-only (`can_write`) and so the container mount topology + the `shared/{X}` fs routing both query it. FK `shared_folder_members.user_id → users(id)` is registry→registry (same file), which is allowed — unlike an owner→registry key.
+- **`create_registry_tables`** — instance-wide, readable without any user key: `users`, `roles`, `llm_providers`, `llm_models`, `transcribe_models`, `tts_models`, `image_generate_models`, `plugins`, `plugin_access` + `plugin_user_configs`, `approval_rules`, `tool_permission_groups`, `config`, `known_tools`, `llm_requests`, `mcp_catalog`, `mcp_global_servers` + `mcp_global_access`, `oauth_providers`, `role_capabilities`, `shared_folders` + `shared_folder_members`. The MCP tables back the Connectors model (§7/§14/§15 — see its own section); `oauth_providers` (accessor `db/oauth_providers.rs`) holds one row per identity provider (Google…) — endpoints + `client_id`/`client_secret` + `redirect_uri`, admin-owned household secrets (§4/§15b), never a per-user token. The last two (accessor `db/shared_folders.rs`) are the **membership** of the on-disk shared folders (§6): a junction table so a member can be read-only (`can_write`) and so the container mount topology + the `shared/{X}` fs routing both query it. FK `shared_folder_members.user_id → users(id)` is registry→registry (same file), which is allowed — unlike an owner→registry key.
 - **`create_owner_tables`** — one owner's content, **identical schema in every file that has it**: `chat_sessions`, `chat_sessions_stack`, `chat_history`, `chat_llm_tools`, `chat_summaries`, `session_scratchpad`, `session_mcp_grants`, `stack_mcp_grants`, `scheduled_jobs`, `job_runs`, `mcp_user_servers`, `mcp_events`, `sources`, `secrets`, `projects`, `project_tickets`, `llm_request_payloads`, `memory_docs` (+ FTS5 `memory_docs_fts`). `mcp_user_servers` (a user's activated per-user connectors) carries `catalog_name` as a **bare `TEXT` snapshot** of `mcp_catalog.name`, never a FK — an owner→registry key would fail every INSERT; for an OAuth connector it also snapshots `oauth_provider` + `deliver_json`, and its `api_key` column holds the refresh token (in the SQLCipher-encrypted file, so no column crypto). Because `memory_docs` is an owner table, one definition backs **private** memory in each `{userid}.db` and **shared** memory in `system.db` (the household owner) — see the memory namespace note below.
 
 Schema is greenfield (no migrations, §0), but a purely **additive** column lands on an existing DB in place: `db::ensure_column` runs `ALTER TABLE … ADD COLUMN` and swallows the "duplicate column" error, a no-op on a fresh DB where the `CREATE TABLE` already has the column. Used for the OAuth columns on `mcp_catalog` / `mcp_user_servers` so a dev box need not be wiped for an additive change (a full recreate is still valid).
@@ -293,6 +297,8 @@ All extend `LightElement` from `web/lib/base.js` (Lit). `ChatSession` (`web/lib/
 | `approval-rules.js` | `<approval-rules-page>` | Approval rule management |
 | `cron-jobs.js` | `<cron-jobs-page>` | Scheduled job management |
 | `connectors.js` | `<connectors-page>` | MCP Connectors list (one row per connector): user activate/deactivate + granted globals; admin gets a **Sign-in providers** modal (OAuth client creds) + Catalog/Marketplace nav (§7/§14/§15) |
+| `plugins-page.js` | `<plugins-page>` | `#plugins` — user: granted plugins + schema-driven per-user config form; admin: enable toggle, instance config, per-user access checklist |
+| `plugin-page-host.js` | `<plugin-page-host>` | Host for plugin-contributed pages (`#plugin/<plugin_id>/<page_id>`): dynamic-imports the fragment module, registers its element, mounts it with `plugin-id` |
 | `connector-detail.js` | `<connector-detail-page>` | A connector's own page (`#connector?name=X`): env/secret form + Test, the **OAuth login panel** (sign in → paste code → complete, §15), global enable + per-user access grants |
 | `shared/connector-common.js` | (helpers) | Shared Connectors vocabulary: `statusOf` (incl. `needs_login` for a pending OAuth row), `STATUS_LABEL`, schema normalization, `jf` fetch |
 | `llm-providers.js` | `<llm-providers-page>` | LLM provider management |