feat: extension registry with metadata catalog and onboarding integration (#238)

* feat: add extension registry with metadata catalog, CLI, and onboarding integration

Adds a central registry that catalogs all 14 available extensions (10 tools,
4 channels) with their capabilities, auth requirements, and artifact references.
The onboarding wizard now shows installable channels from the registry and
offers tool installation as a new Step 7.

- registry/ folder with per-extension JSON manifests and bundle definitions
- src/registry/ module: manifest structs, catalog loader, installer
- `ironclaw registry list|info|install|install-defaults` CLI commands
- Setup wizard enhanced: channels from registry, new extensions step (8 steps)

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix(setup): resolve workspace errors for tool crates and channels-only onboarding

Tool crates in tools-src/ and channels-src/ failed `cargo metadata` during
onboard install because Cargo resolved them as part of the root workspace.
Add `[workspace]` table to each standalone crate and extend the root
`workspace.exclude` list so they build independently.

Channels-only mode (`onboard --channels-only`) failed with "Secrets not
configured" and "No database connection" because it skipped database and
security setup. Add `reconnect_existing_db()` to establish the DB connection
and load saved settings before running channel configuration.

Also improve the tunnel "already configured" display to show full provider
details (domain, mode, command) instead of just the provider name.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix(registry): address PR review feedback on installer and catalog

- Use manifest.name (not crate_name) for installed filenames so
  discovery, auth, and CLI commands all agree on the stem (#1)
- Add AlreadyInstalled error variant instead of misleading
  ExtensionNotFound (#2)
- Add DownloadFailed error variant with URL context instead of
  stuffing URLs into PathBuf (#3)
- Validate HTTP status with error_for_status() before reading
  response bytes in artifact downloads (#4)
- Switch build_wasm_component to tokio::process::Command with
  status() so build output streams to the terminal (#6)
- Find WASM artifact by crate_name specifically instead of picking
  the first .wasm file in the release directory (#7)
- Add is_file() guard in catalog loader to skip directories (#8)
- Detect ambiguous bare-name lookups when both tools/<name> and
  channels/<name> exist, with get_strict() returning an error (#9)
- Fix wizard step_extensions to check tool.name for installed
  detection, consistent with the new naming (#11, #12)
- Fix redundant closures and map_or clippy warnings in changed files

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix(setup): restore DB connection fields after settings reload

reconnect_postgres() and reconnect_libsql() called Settings::from_db_map()
which overwrote database_url / libsql_path / libsql_url set from env vars.
Also use get_strict() in cmd_info to surface ambiguous bare-name errors.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* style: fix clippy collapsible_if and print_literal warnings

Collapse nested if-let chains and inline string literals in format
macros to satisfy CI clippy lint checks (deny warnings).

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix(registry): prefer artifacts for install-defaults and improve dir lookup

- InstallDefaults now defaults to downloading pre-built artifacts
  (matching `registry install` behavior), with --build flag for source builds.
- find_registry_dir() walks up 3 ancestor levels from the exe and adds
  a CARGO_MANIFEST_DIR fallback, matching load_registry_catalog() logic.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

---------

Co-authored-by: Claude Opus 4.6 <[email protected]>

registry/channels/whatsapp.json

@@ -0,0 +1,31 @@
+{
+  "name": "whatsapp",
+  "display_name": "WhatsApp",
+  "kind": "channel",
+  "version": "0.1.0",
+  "description": "WhatsApp Cloud API channel for receiving and responding to messages",
+  "keywords": ["messaging", "chat", "whatsapp", "meta"],
+
+  "source": {
+    "dir": "channels-src/whatsapp",
+    "capabilities": "whatsapp.capabilities.json",
+    "crate_name": "whatsapp-channel"
+  },
+
+  "artifacts": {
+    "wasm32-wasip2": {
+      "url": null,
+      "sha256": null
+    }
+  },
+
+  "auth_summary": {
+    "method": "manual",
+    "provider": "Meta",
+    "secrets": ["whatsapp_access_token", "whatsapp_verify_token"],
+    "shared_auth": null,
+    "setup_url": "https://developers.facebook.com/apps/"
+  },
+
+  "tags": ["messaging"]
+}