feat: bootstrap vela UI and gateway workspace

Establish the monorepo, tooling, and starter apps so UI and gateway development can begin from a documented, runnable baseline.

docs/integrations.md

@@ -0,0 +1,97 @@
+# Vela Integrations and Tool Safety
+
+## Current Runtime Baseline
+
+- `vela-ui` is implemented as a SvelteKit application
+- `vela-gateway` is implemented as a Fastify service
+- current integration work beyond the gateway HTTP baseline remains future implementation
+
+## STT (Speech-to-Text)
+
+### Primary Option
+
+- `whisper.cpp`
+
+### Deployment
+
+- start on NanoPi
+- move to NAS if latency is insufficient
+
+### Requirements
+
+- streaming transcription
+- partial and final output
+- low latency, with sub-second response preferred
+
+## TTS (Text-to-Speech)
+
+### Engine
+
+- Kokoro TTS
+
+### Deployment
+
+- prefer NAS for more compute headroom
+
+### API Contract
+
+```http
+POST /speak
+{
+  "text": "...",
+  "voice": "vela",
+  "format": "wav"
+}
+```
+
+### Requirements
+
+- streaming audio preferred
+- low startup latency
+- interrupt support
+
+## Tool System
+
+### Home Assistant Tool
+
+#### Functions
+
+```ts
+turn_on(entity_id);
+turn_off(entity_id);
+set_temperature(entity_id, value);
+get_state(entity_id);
+```
+
+#### Backend
+
+- REST API
+- optional Conversation API
+
+#### Safety
+
+- require confirmation for destructive actions
+- require confirmation for irreversible or significant state changes
+- keep secrets server-side only
+
+### SearXNG Tool
+
+#### Endpoint
+
+```http
+GET /search?q=...&format=json
+```
+
+#### Flow
+
+- query SearXNG
+- return top results
+- let the LLM summarize the result set
+
+## Safety Rules
+
+- the LLM does not directly control systems
+- all external actions go through explicit tool adapters
+- Home Assistant write actions require confirmation
+- frontend must not contain Home Assistant tokens or other secrets
+- ambiguous tool intents should be clarified instead of guessed