WIP: restore custom completion and embedding endpoints

[JegernOUTT]

Summary

WIP task-planner implementation for restoring custom completion and embedding endpoint support.

Current included cards:

• T-1: endpoint-style taxonomy and role contract foundations
• T-3: capability-aware CustomProvider runtime

Planned follow-up cards will continue landing on this branch:

• backend caps/default selection
• provider HTTP/API roundtrip
• completion and embedding adapters
• GUI role-separated config/defaults
• mock-server coverage and final compatibility sweep

Verification so far

• cargo test -p refact-core provider_types
• cargo test -p refact-core llm_types
• cargo test -p refact-caps-core provider_config
• cargo test -p refact-caps-core model_records
• cargo test -p refact-providers custom
• cargo test -p refact-providers instance

Notes

Draft/WIP PR. More commits will be pushed as task cards complete.

[JegernOUTT]

🔀 Merged latest main into feature/completion_emb_revival

Pushed merge commit 22409e124 (22042c0c1..22409e124).

main shipped the new Refact UI kit (SettingsSection / SettingItem / Field / kit ModelSelector / Tabs, panel-less glass design, lucide icons) while this branch still used the old Radix Card/Flex/Text panels. The new design wins everywhere; the role-separated custom completion + embedding feature was re-implemented on top of it.

Conflict resolutions

Area	Resolution
engine/global_context.rs	merged atomic imports (AtomicU64 + AtomicUsize)
ModelSelector.tsx	kit base + re-added capability (chat/completion/embedding)
ModelSamplingParams.tsx	kit base + capability axis (embedding hidden, completion ctx)
DefaultModels.tsx (+test)	tabbed SettingsSection + Completion & Embedding role tabs
ProviderForm.tsx	kit base + re-wired RoleSeparatedModelConfig for custom providers
RoleSeparatedModelConfig.tsx	rewritten in Field/Select/SettingsGroup kit (aria-labels preserved)
FormSelect.tsx, ModelSelector/AddCustomModel tests	took main's new-design versions
RichModelSelectItem.*	deleted — superseded by kit ModelSelector
modelProviders.ts (+test)	reverted to main's vendor-detection (dropped feature prefix-first grouping that conflicted with main's authoritative test)
ModelCardPopup.tsx	orphaned Radix <Text> → tokenized markup

Verification

• Engine: cargo check -p refact-lsp → exit 0 (3 pre-existing benign warnings)
• GUI: npm run types ✅ · npm run lint ✅ (0 warnings) · full vitest 2599 passed / 0 failed

Note: the feature's "prefix-first" model grouping (custom/…→custom) was dropped during the merge because it was incompatible with main's openai/claude-…→Anthropic test stub. Display-grouping only; no functional impact.

[JegernOUTT]

Re-synced with main (5263 commits) — all green

Merged latest origin/main into feature/completion_emb_revival.

• Merge commit 8e2dbdffd (parents: feature a919a3a78 + main 43a3296a8) — 0 textual conflicts.
• One semantic merge fix (f89d93b9d): main added the new OpenCodeProvider, but this branch added required completion_endpoint_style / embedding_endpoint_style fields to ProviderRuntime. Added String::new() defaults to the OpenCode runtime initializer (chat-only provider, matches anthropic/deepseek pattern).

Verification (all green)

• Engine: cargo check -p refact-lsp → exit 0
• Engine: cargo test -p refact-providers --lib → 150 passed / 0 failed
• GUI: npm run types → ok · npm run lint → 0 warnings · npm run test → 246 files, 2865 passed / 7 skipped

Role-separated completion/embedding restoration behavior preserved; main's new UI kit remains authoritative.

[JegernOUTT]

CI note: x86_64-linux engine job failure is a pre-existing infra issue, not from this re-sync

Engine CI run 28455727893 — job dist (x86_64-unknown-linux-gnu) fails in a dependency build script, not our code:

aws-lc-sys-0.42.0/builder/cc_builder.rs:872: ### COMPILER BUG DETECTED ###
Your compiler (cc) is not supported due to a memcmp related bug (gcc bug 95189)

Root cause / why it's not introduced here:

• aws-lc-sys enters via rmcp 1.5.0 → rustls 0.23 → aws-lc-rs — all from main's dependency bumps.
• Cargo.lock is gitignored/untracked, so CI resolves deps fresh each build.
• Engine Cargo.toml, .github/ workflows, .cargo/ config, and toolchain are byte-identical to main → main's engine build resolves identically and hits the same panic.

This re-sync's code is independently green: cargo check -p refact-lsp exit 0, cargo test -p refact-providers 150 passed, GUI types/lint/test all green (2865 tests). Windows/macOS dist jobs (non-GCC toolchains) build the same code fine.

Fixing the GCC/aws-lc-sys incompatibility (force ring backend, or set CC=clang in CI) is a main-scoped infra change and should land on main, then merge — not diverge here.

[JegernOUTT]

Fixed a real test-build regression caught by CI (commit 8e221ce15)

The previous run surfaced a genuine compile error (separate from the aws-lc-sys infra issue) — all 3 Windows jobs failed at the test step:

error[E0063]: missing fields `auth_token` and `extra_headers`
  --> src/tools/tools_list.rs:863  (EmbeddingModelConfig)

A #[cfg(test)] mock initializer didn't get the two fields this branch added to EmbeddingModelConfig. My local cargo check -p refact-lsp missed it because it doesn't compile tests; macOS/aarch64 cross-jobs skip native test compilation, so only native Windows caught it.

Fix + verification:

• Added auth_token: String::new() + extra_headers: HashMap::new() to the mock.
• cargo check --workspace --all-targets → clean (no other broken initializers).
• cargo test -p refact-lsp --lib → 4112 passed / 0 failed.

Pushed as 8e221ce15; fresh CI run 28459593155 is validating. The only expected remaining red is dist (x86_64-linux) on the inherited aws-lc-sys/GCC infra issue documented above.

[JegernOUTT]

✅ Final CI verdict — 6/7 green; only the known aws-lc-sys/GCC infra target is red

Run 28459593155 (commit 8e221ce15):

Target	Result
dist x86_64-windows	✅
dist aarch64-windows	✅
dist i686-windows	✅
dist aarch64-macos	✅
dist aarch64-linux	✅
daemon E2E linux	✅
dist x86_64-linux	❌ inherited aws-lc-sys/GCC (bug 95189)

The EmbeddingModelConfig test-mock fix (8e221ce15) cleared all 3 Windows failures. aarch64-linux also passes (cross-compile dodges the native-GCC aws-lc-sys guard), which pinpoints the remaining red as the x86_64-linux runner's GCC tripping aws-lc-sys — a main-inherited infra issue, not this branch's code. Every actual code problem from the 5263-commit catch-up is fixed (2 struct-field merge breaks: opencode.rs, tools_list.rs).

Local verification green: engine cargo check --workspace --all-targets, cargo test -p refact-lsp --lib (4112 passed), GUI types/lint/test (2865 passed).