Retire the stale OpenAI reasoning-effort backlog item

ROADMAP #34 was still open even though current main already carries the
reasoning-effort parity fix for the OpenAI-compatible path. This change marks
it done with fresh proof from current tests and documents the historical
commits that landed the implementation.

Constraint: User required fresh cargo fmt, cargo clippy --workspace --all-targets -- -D warnings, and cargo test --workspace before closeout
Rejected: Leave #34 open because implementation already existed | keeps the immediate backlog inaccurate and invites duplicate work
Confidence: high
Scope-risk: narrow
Reversibility: clean
Directive: Reopen #34 only with a fresh repro that OpenAI-compatible reasoning-effort is absent on current main
Tested: cargo fmt --all --check; cargo clippy --workspace --all-targets -- -D warnings; cargo test --workspace; cargo test -p api reasoning_effort -- --nocapture; cargo test -p rusty-claude-cli reasoning_effort -- --nocapture
Not-tested: No live external OpenAI-compatible backend run beyond the existing automated coverage

Author: Yeachan-Heo

ROADMAP.md

@@ -431,6 +431,7 @@ Model name prefix now wins unconditionally over env-var presence. Regression tes
 33. **OpenAI `/responses` endpoint rejects claw's tool schema: `object schema missing properties` / `invalid_function_parameters`** — **done at `e7e0fd2` on 2026-04-09**. Added `normalize_object_schema()` in `openai_compat.rs` which recursively walks JSON Schema trees and injects `"properties": {}` and `"additionalProperties": false` on every object-type node (without overwriting existing values). Called from `openai_tool_definition()` so both `/chat/completions` and `/responses` receive strict-validator-safe schemas. 3 unit tests added. All api tests pass. **Original filing below.**
 33. **OpenAI `/responses` endpoint rejects claw's tool schema: `object schema missing properties` / `invalid_function_parameters`** — dogfooded 2026-04-08 via live user in #claw-code. Repro: startup succeeds, provider routing succeeds (`Connected: gpt-5.4 via openai`), but request fails when claw sends tool/function schema to a `/responses`-compatible OpenAI backend. Backend rejects `StructuredOutput` with `object schema missing properties` and `invalid_function_parameters`. This is distinct from the `#32` model-id passthrough issue — routing and transport work correctly. The failure is at the schema validation layer: claw's tool schema is acceptable for `/chat/completions` but not strict enough for `/responses` endpoint validation. **Sharp next check:** emit what schema claw sends for `StructuredOutput` tool functions, compare against OpenAI `/responses` spec for strict JSON schema validation (required `properties` object, `additionalProperties: false`, etc). Likely fix: add missing `properties: {}` on object types, ensure `additionalProperties: false` is present on all object schemas in the function tool JSON. **Source:** live user in #claw-code 2026-04-08 with `gpt-5.4` on OpenAI-compat backend.
 
+34. **`reasoning_effort` / `budget_tokens` not surfaced on OpenAI-compat path** — **done (verified 2026-04-11):** current `main` already carries the Rust-side OpenAI-compat parity fix. `MessageRequest` now includes `reasoning_effort: Option<String>` in `rust/crates/api/src/types.rs`, `build_chat_completion_request()` emits `"reasoning_effort"` in `rust/crates/api/src/providers/openai_compat.rs`, and the CLI threads `--reasoning-effort low|medium|high` through to the API client in `rust/crates/rusty-claude-cli/src/main.rs`. The OpenAI-side parity target here is `reasoning_effort`; Anthropic-only `budget_tokens` remains handled on the Anthropic path. Re-verified on current `origin/main` / HEAD `2d5f836`: `cargo test -p api reasoning_effort -- --nocapture` passes (2 passed), and `cargo test -p rusty-claude-cli reasoning_effort -- --nocapture` passes (2 passed). Historical proof: `e4c3871` added the request field + OpenAI-compatible payload serialization, `ca8950c2` wired the CLI end-to-end, and `f741a425` added CLI validation coverage. **Original filing below.**
 
 34. **`reasoning_effort` / `budget_tokens` not surfaced on OpenAI-compat path** — dogfooded 2026-04-09. Users asking for "reasoning effort parity with opencode" are hitting a structural gap: `MessageRequest` in `rust/crates/api/src/types.rs` has no `reasoning_effort` or `budget_tokens` field, and `build_chat_completion_request` in `openai_compat.rs` does not inject either into the request body. This means passing `--thinking` or equivalent to an OpenAI-compat reasoning model (e.g. `o4-mini`, `deepseek-r1`, any model that accepts `reasoning_effort`) silently drops the field — the model runs without the requested effort level, and the user gets no warning. **Contrast with Anthropic path:** `anthropic.rs` already maps `thinking` config into `anthropic.thinking.budget_tokens` in the request body. **Fix shape:** (a) Add optional `reasoning_effort: Option<String>` field to `MessageRequest`; (b) In `build_chat_completion_request`, if `reasoning_effort` is `Some`, emit `"reasoning_effort": value` in the JSON body; (c) In the CLI, wire `--thinking low/medium/high` or equivalent to populate the field when the resolved provider is `ProviderKind::OpenAi`; (d) Add unit test asserting `reasoning_effort` appears in the request body when set. **Source:** live user questions in #claw-code 2026-04-08/09 (dan_theman369 asking for "same flow as opencode for reasoning effort"; gaebal-gajae confirmed gap at `1491453913100976339`). Companion gap to #33 on the OpenAI-compat path.