v3.3.0 GUI dashboard + reports + model expansion + root fix

Engine:
- Fix: inject IS_SANDBOX=1 so Claude Code's --dangerously-skip-permissions
  works under root (real backend runs were exiting rc=1 immediately)
- models: expand to 40 models / 13 providers, tagged CLI vs API
  (NVIDIA NIM, DeepSeek, Mistral, Qwen/DashScope, Groq, Together, OpenRouter,
  Ollama, Gemini) — Qwen/DeepSeek/Llama usable via API
- backends: on_start callback surfaces the exact argv ("what runs behind it")
- orchestrator: require a Playwright screenshot per confirmed finding; collect
  results/activity.json; auto-generate reports after a run
- report.py: HTML always + PDF via Typst engine (.typ source emitted too)

Web dashboard (webgui/, stdlib only — no npm/build):
- Sidebar dashboard (PentAGI-style): Run / Agents / Insights / Reports / Settings
- Multi-target runs; live execution console + per-task activity; finding cards
  with screenshots; backend+provider+model pickers (CLI & API)
- Agents tab: browse 213 + add new .md agents from the UI
- Insights: interactive RL-weight + severity charts
- Reports: download/preview PDF + HTML
- Settings/API: execution mode, per-provider API keys, orchestrator, verbosity
- Endpoints: /api/agents (GET/POST), /api/rl, /api/config, /api/reports,
  /reports/* + /shots/* static serving

Cleanup: retire replaced web stack (frontend React, FastAPI backend, core
orchestration, old test) to legacy/. Active engine + GUI are fully standalone.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

legacy/frontend_react/public/favicon.svg

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