Add Client::chat with the first-byte wait, liveness and error mapping

Implemented-By: OpenCode session (model recorded in docs/implementer-log.md)

docs/implementer-log.md

@@ -24,6 +24,7 @@ reviewer adds findings under "Reviews" once per milestone.
 | M2a/07-llama-assemble | 2026-09-18 | done | 3 | fail | none | Wrote crates/loopd/src/llama/assemble.rs (Assembler plus server-format Chunk/Choice/Delta/ToolCallPiece/FunctionPiece/PromptProgress structs with no deny_unknown_fields) and registered `pub mod assemble;`. Accumulation: text goes through get_or_insert_with so content/reasoning stay None until a non-empty piece arrives; tool-call pieces land by index via u32::try_from then usize::try_from and get_mut, a new call only at exactly the end, a skip-ahead or an out-of-range index is Protocol; timings update before the reasoning-token count reads predicted_n; finish checks finish_reason (StreamClosedEarly), then id, then every tool call has id and name. First gate failed on two clippy collapsible_if lints; rewrote the two nested ifs as edition-2024 let-chains and re-ran. All 7 assemble tests pass; `make gate` prints `gate: ok`. | GLM-5.3 (z.ai, default settings) |
 | M2a/08-llama-info | 2026-09-18 | done | 2 | fail | none | Wrote crates/loopd/src/llama/info.rs and registered `pub mod info;`. `call` is one exchange: open socket, set read timeout to `liveness_ms`, send, read head, `read_capped` with `MAX_BODY`; non-200 returns `InferError::Http { status, error_text(&bytes) }`, everything else maps through `map_http` (Connect->Connect, Timeout->Stalled, Closed->StreamClosedEarly, else->Protocol). `error_text` reads the full body via `from_utf8_lossy` then backs up from byte 4096 to a char boundary, so a cut mid-character does not panic. `props` reads `chat_template`, `total_slots`, and `default_generation_settings.n_ctx` from the JSON (unknown fields ignored); `slots` deserializes `Vec<SlotInfo>`; `tokenize` POSTs `{"model","content"}` via `serde_json` and returns `tokens.len()`. `cache_outcome` uses `saturating_add` and `current.cache_n + CACHE_TOLERANCE >= expected`. All 7 tests pass; first gate run failed on rustfmt import order, fixed with `cargo fmt --all`. | ? |
 | M2a/11-llama-gate-retry | 2026-09-18 | stopped | 0 | n/a | none | The prerequisite `chat` is missing, so this task is impossible as written. The branch is at M2a/07 (assemble); task 09 (llama-chat) has not been done and `crates/loopd/src/llama/chat.rs` does not exist. The retry.rs test calls `client.chat()` and `chat_with_retry()`, and the task says to *modify* chat.rs and add the gate inside `chat` — all of which require a `chat` that was never implemented. The gate and retry pieces are independent of chat, but the 13-test suite cannot pass (it does not even compile) without it. Did not read task 09 per AGENTS.md and did not implement chat, which is another task and would be improvising. Committed only this log row; the copied tests/retry.rs was removed. | ? |
+| M2a/09-llama-chat | 2026-09-18 | done | 1 | pass | none | Wrote crates/loopd/src/llama/chat.rs (`chat`, with the head wait in a separate `wait_for_head`) and registered `pub mod chat;`. `chat` builds the body (build error -> Protocol), opens and POSTs, then `wait_for_head` loops `read_head` at `poll_ms`: a Timeout is classified Idle/Busy/Unavailable by `received_any` then a `slots()` poll, emits `Waiting { slot_busy }` on every poll, keeps a per-state `since` that resets on state change, and returns `WaitTimeout`/`LoadTimeout`/`Stalled` at the right limits; 200 streams via `Events`+`Assembler` mapping `Timeout->Stalled`, `Truncated->StreamClosedEarly`, else `Protocol`, then `finish(false)`; non-200 returns `Http { status, error_text }`. All 13 chat tests pass five runs in a row. Table-to-test map: state (table 1) Busy -> a_busy_slot_is_waited_out / a_slot_that_stays_busy_is_a_wait_timeout, Idle-not-processing -> only_the_requests_own_slot_counts_as_busy, Unavailable -> an_unavailable_server_is_a_load_timeout, Idle-received_any -> a_slow_but_steady_stream_is_not_a_stall (turn1 head is 738 B, pieces are 3140/8=392 B, so the head-wait times out with a partial head); thresholds (table 2) -> a_slot_that_stays_busy_is_a_wait_timeout / an_unavailable_server_is_a_load_timeout / only_the_requests_own_slot_counts_as_busy; stream (table 3) Data/Done/None -> the recorded completion and trickle tests, Timeout -> silence_in_mid_stream_is_a_stall, Truncated -> a_stream_that_is_cut_is_closed_early_wherever_the_cut_falls, other -> garbage_in_the_stream_is_a_protocol_error; clock-restart -> the_wait_clocks_restart_when_the_state_changes. One path fix: info and request live under crate::llama, not crate::, so the imports use crate::llama::{info::..., request::...}. | ? |
 
 
 ## Reviews