feat: add get_shape_library tool for AI icon discovery (#335)

* feat: add get_shape_library tool for AI icon discovery

- Add server-side tool that returns shape library documentation
- AI can fetch icon/shape names on-demand before generating diagrams
- Includes path traversal protection and input sanitization
- Library index embedded in tool description for discoverability
- Supports 33 libraries: AWS, Azure, GCP, Kubernetes, Cisco, etc.

* fix: improve get_shape_library error handling and imports

- Move fs/path imports to top of file (avoid dynamic imports per call)
- Distinguish file-not-found vs other errors in catch block
- Include invalid input in validation error message
- Log unexpected errors for debugging

* docs: add get_shape_library to system prompt tool list

- Add Tool4 (get_shape_library) to available tools section
- Add usage guidance in 'Choose the right tool' section
- Update AWS icons note to reference get_shape_library for icon discovery

* fix: display get_shape_library tool output in chat UI

* fix: correct state check for get_shape_library output display

* fix: make get_shape_library output respect fold state

* style: auto-format with Biome

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Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

docs/shape-libraries/citrix.md

@@ -0,0 +1,115 @@
+# citrix
+
+**Type:** mxgraph shapes
+**Prefix:** `mxgraph.citrix`
+
+## Usage
+
+```xml
+<mxCell value="label" style="shape=mxgraph.citrix.{shape};fillColor=#00A4E4;strokeColor=none;" vertex="1" parent="1">
+  <mxGeometry x="0" y="0" width="60" height="60" as="geometry" />
+</mxCell>
+```
+
+
+
+## Shapes (98)
+
+- `1u_2u_server`
+- `access_card`
+- `branch_repeater`
+- `browser`
+- `cache_server`
+- `calendar`
+- `cell_phone`
+- `chassis`
+- `citrix_hdx`
+- `citrix_logo`
+- `cloud`
+- `command_center`
+- `database`
+- `database_server`
+- `datacenter`
+- `desktop`
+- `desktop_web`
+- `dhcp_server`
+- `directory_server`
+- `dns_server`
+- `document`
+- `edgesight_server`
+- `file_server`
+- `firewall`
+- `ftp_server`
+- `geolocation_database`
+- `globe`
+- `goto_meeting`
+- `government`
+- `home_office`
+- `hq_enterprise`
+- `inspection`
+- `ip_phone`
+- `kiosk`
+- `laptop_1`
+- `laptop_2`
+- `license_server`
+- `merchandising_server`
+- `middleware`
+- `mxgraph.citrix`
+- `netscaler_gateway`
+- `netscaler_mpx`
+- `netscaler_sdx`
+- `netscaler_vpx`
+- `pbx_server`
+- `pda`
+- `podio`
+- `printer`
+- `process`
+- `provisioning_server`
+- `proxy_server`
+- `radius_server`
+- `remote_office`
+- `reporting`
+- `role_appcontroller`
+- `role_applications`
+- `role_cloudbridge`
+- `role_desktops`
+- `role_load_testing_controller`
+- `role_load_testing_launcher`
+- `role_receiver`
+- `role_repeater`
+- `role_secure_access`
+- `role_security`
+- `role_services`
+- `role_storefront`
+- `role_storefront_services`
+- `role_synchronizer`
+- `role_xenmobile`
+- `role_xenmobile_device_manager`
+- `router`
+- `security`
+- `sharefile`
+- `site`
+- `smtp_server`
+- `storefront_services`
+- `switch`
+- `tablet_1`
+- `tablet_2`
+- `thin_client`
+- `tower_server`
+- `user_control`
+- `users`
+- `web_server`
+- `web_service`
+- `worxenroll`
+- `worxhome`
+- `worxmail`
+- `worxweb`
+- `xenapp_server`
+- `xenapp_services`
+- `xenapp_web`
+- `xencenter`
+- `xenclient`
+- `xenclient_synchronizer`
+- `xendesktop_server`
+- `xenmobile`
+- `xenserver`