chore: snapshot working tree - pty_exited notifications + in-flight inference WIP

feat(booterm): structured pty_exited WS notifications. Plan-validated, impl-validated, code-reviewed green (contracts build clean, contracts test 29/29, booterm + web typecheck clean).

wip: in-progress inference/provider refactor (agents.ts, provider.ts, new llama-providers.ts, removed llama-args-validator), plus arena, dispatcher, compaction, schema changes.

openspec: pty-exit-notifications complete; x-agent-flags planned (not yet implemented).

openspec/changes/multi-llama-swap-providers-model-favorites/proposal.md

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+# multi-llama-swap-providers-model-favorites
+
+## Why
+
+BooCode still treats local inference as a single `LLAMA_SWAP_URL`, but the
+actual setup is already a fleet:
+
+- `sam-desktop` at `100.101.41.16:8401`
+- `embedding` at `100.90.172.55:8411`
+- optional DeepSeek cloud models when `DEEPSEEK_API_KEY` is set
+
+The current model identity is only a bare model string, which is no longer
+safe. Five model IDs already exist on both llama-swap hosts, the seeded
+`DEFAULT_MODEL` has already drifted out of the live list once, and multiple
+server/coder call sites still hardcode a single upstream.
+
+The research in
+`docs/research/2026-06-10-multi-llama-swap-providers-model-favorites.md`
+validated one direction:
+
+1. Introduce a named provider registry.
+2. Store selected models as composite IDs: `provider/model`.
+3. Group pickers by provider with a Favorites section first.
+4. Persist favorites server-side so BooChat and BooCoder share them.
+5. Remove single-endpoint assumptions from routing, context lookup,
+   compaction, arena, and coder dispatch.
+
+This batch is also the prerequisite named in `openspec/changes/boocontrol/`.
+
+## What Changes
+
+1. Add a shared provider-registry config for local model providers.
+2. Replace bare model identity with composite `provider/model` IDs at the API,
+   picker, cache, and routing layers while keeping legacy bare IDs readable.
+3. Convert the server model catalog from a flat list into grouped provider
+   sections with favorites surfaced first.
+4. Make sidecar routing an attribute of the `sam-desktop` provider instead of
+   a global default for all non-DeepSeek traffic.
+5. Update BooCoder's llama-swap namespace bridge so composite IDs still
+   dispatch through opencode correctly.
+6. Add server-side favorite persistence in `settings` with hide-not-delete
+   behavior for unavailable models.
+
+## Non-goals
+
+- Replacing the existing ACP provider registry in `data/coder-providers.json`
+- Introducing llama-swap peer federation or LiteLLM as an aggregation layer
+- Adding full-text search, tags, or admin curation to the pickers in this batch
+- Cleaning up stale favorites automatically
+- Reworking session/chat schema columns from `TEXT` to structured provider fields
+
+## Success Criteria
+
+- `GET /api/models` returns a provider-aware catalog that can distinguish
+  duplicate model names across hosts.
+- Existing sessions/chats that store a bare model ID still work, resolving to
+  the default local provider without data migration.
+- `embedding/deepseek-r1-qwen3-8b` never routes to DeepSeek cloud and never
+  receives the fake static 131k context window.
+- Requests for `embedding/*` models never go through llama-sidecar.
+- BooChat and BooCoder both render a Favorites section first, then provider
+  groups, and a favorited model still remains visible in its provider group.
+- A favorite for an offline provider disappears from the visible list but
+  returns automatically when that provider comes back.
+- Arena, compaction, task-model, and model-context all resolve the same
+  provider/model pair consistently.
+
+## Deliverables
+
+| Doc | Purpose |
+|-----|---------|
+| [`design.md`](./design.md) | Registry shape, model identity rules, routing, UX, rollout |
+| [`tasks.md`](./tasks.md) | Ordered implementation and verification checklist |