LCFS - AI Chatbot Assistant

**Description:**
AI-powered assistant to help users with LCFS compliance, reporting, fuel codes, and portal navigation. Provides instant answers using LCFS documentation.

**Wireframe:** [UXPin Prototype](https://preview.uxpin.com/e0e2f15fc1b52987fd0287ad8c8103452dd16d60#/pages/213069001/simulate/no-panels)

**Purpose and benefit to user:**
Instant 24/7 help for LCFS questions, reduced support wait times, and improved user experience navigating the portal.

**Acceptance Criteria:**

- [ ] Given I click "LCFS Assistant", When chat opens, Then I see personalized welcome and suggested questions
- [ ] Given I ask a question, When assistant responds, Then I see real-time streaming text with typing indicator
- [ ] Given I receive a response, When I interact with it, Then I can copy, listen (text-to-speech), or regenerate
- [ ] Given I sent a message, When I want to change it, Then I can edit and resend
- [ ] Given I have a conversation, When I click download/clear, Then I can export or reset the chat
- [ ] Given I close and reopen chat, When it loads, Then I see a fresh conversation
- [ ] Given I'm on mobile (<650px), When chat opens, Then it displays full-screen
- [ ] Given I'm on desktop, When using chat, Then I can minimize/maximize the window
- [ ] Given I view the footer, When I read it, Then I see Privacy link, Support link, and AI disclaimer

**Development Checklist:**
- [ ] Floating button with BC Gov styling
- [ ] Chat window with header actions (download, clear, max/min, close)
- [ ] Streaming AI responses via RAG/Ollama
- [ ] Message actions: copy, text-to-speech, edit, regenerate
- [ ] Mobile-responsive (full-screen on mobile)
- [ ] Footer with Privacy, Support links, and disclaimer

**Notes:**
- Uses RAG pipeline with LCFS documentation
- Disclaimer: "AI-generated responses may be inaccurate. Verify important information."
- Related: #3544 (Support Escalation Form)
- Related: #3548 (Feature Flag for controlled rollout)