Certified local mode: managed on-device model with verified setup and egress guard #1162

Data teams in compliance-bound environments (finance, healthcare) cannot send warehouse schemas, query results, or dbt project contents to cloud LLM providers — today that rules altimate-code out for them entirely, or forces a hand-rolled Ollama/LM Studio setup with no verification that the endpoint actually works for agent workloads (tool calls, long-context prefill, reasoning renders).

Proposal: a managed local mode — altimate local — that makes the local path a first-class, verified experience:

• one command: hardware detection → pinned, SHA-256-verified model + runtime download → server lifecycle on 127.0.0.1 → certification probes (tool-call round trip, reasoning render, 8K prefill) that must pass before any config is touched
• a model registry (multi-model by design; --model <id>, altimate local models)
• an egress guard: wiring local mode adds ask permission rules for the web tools (websearch/webfetch/codesearch) so a local-first session reaches the internet only with per-step approval; reversible, never overwrites user-set permissions
• context diet for small-context local models (skill-listing compaction under the existing ALTIMATE_TOOL_RETRIEVAL flag)
• first-run TUI picker row + docs integration so the option is discoverable

Out of scope for the first cut (tracked as follow-ups): Linux AMD/Intel GPU auto-detection (runtime already works via Vulkan), native-Windows certification, live prefill progress in the TUI.