Review view: chat process display - #457

…idate show_process before the managed request

Three review findings on the show_process weave, all red-verified:

- _weave nested every tool result under the most recent [tool] line,
  which misattributes results when a turn makes parallel calls (the SDK
  streams all calls, then all results). A result now nests only when the
  line above is its own call (by call_id); otherwise it stands alone
  with its call's clipped arguments echoed, so same-name parallel calls
  stay tellable apart. Hidden-call mode falls out unchanged (no stored
  arguments, no echo).

- Empty deltas now stop at the event source. chat_completions and the
  managed chunk lane both filter them; the new local lane did not, so a
  mid-stream "" (litellm forwards annotated/provider-field empties)
  leaked into the bare view and flipped _weave sections, splitting one
  thinking burst into repeated labels.

- The managed streaming lane sent the billed request before
  _process_options ran, so a config typo cost a real chat call. chat()
  now chokes on bad show_process before dispatching, matching the local
  lane's validate-first order.

Two docstring truths: close()'s "a run never consumed never starts"
holds only for own-model chat (the managed request is already on the
wire), and the module docstring now covers the managed chunk weave.

456 tests green; the three new ones red-verified; managed-lane paths
re-run with the agents package blocked; pyright adds nothing on touched
lines.

Claude-Session: https://claude.ai/code/session_01XeeD2214z6Vd6qKcAi9ZvJ

…am overloads

Four review fixes plus two coverage gaps, each red- or
mutation-verified:

- _cloud_chunk_events treated any non-tool_use tag inside an open tool
  block as answer text, so argument JSON leaked into the
  show_process=False answer — the one meant to be appended back as
  conversation history. Inside an open block nothing is answer:
  argument chunks now accumulate under any tag. And non-string
  argument pieces stringify at the join instead of killing the whole
  stream with a raw TypeError.

- _process_options sorted unknown keys before repr-ing them, so
  mixed-type keys ({1: True, "foo": 1}) raised a bare TypeError past
  the caller's `except PageIndexAPIError`; sorting the reprs keeps the
  single error type.

- chat() gains @overload on stream, so the docstring's own `.events`
  usage type-checks for py.typed consumers (previously pyright ruled
  `Cannot access attribute "events" for class "str"` on the exact
  documented snippet). pageindex/ error count unchanged (234).

- Coverage: the streaming lane's whole `finally` could be deleted with
  the suite still green — the new abandonment test pins the teardown
  (pump exits, turn 2 emits nothing, _aclose_backend closes the
  per-call client). And FakeModel emitted only the reasoning event
  production never sends (litellm folds reasoning into
  reasoning_content, which arrives as summary deltas); it now
  alternates variants, so dropping either from the isinstance tuple
  goes red.

459 tests green; managed-path tests re-run with the agents package
blocked; flake8 parity on every touched file.

Claude-Session: https://claude.ai/code/session_01DWBCCTDzwuVamBf5MvQ4eP

…sy show_process message

ChatStream.events was a property whose getter latched the stream's one
view on mere attribute access: a debugger variable pane, hasattr, or
getattr(stream, "events", None) — which PageIndexAPIError escapes, as
getattr only swallows AttributeError — was enough to make a later
`for chunk in stream:` refuse, with nothing consumed. The getter now
returns a lazy generator: the managed refusal, the view claim and the
run start all happen on first consumption, so introspection is
side-effect free and the text view stays usable after a probe.

And the stream=False guard's message told falsy-but-not-False values
("show_process=0", "") that they passed show_process=True; the check
itself is the ruled falsy-{} trap and stands, but the message now
names the off values and echoes what was got.

461 tests green (2 red-verified new: inert read on both lanes, plus
the falsy-message case); changed managed-path tests re-run with the
agents package blocked; pyright pageindex/ 234 -> 234.

Claude-Session: https://claude.ai/code/session_01DWBCCTDzwuVamBf5MvQ4eP

[tool_call] and [tool_result] replace the "[tool]" label and the "->"
arrow, so the text view's labels are exactly the .events type names
(config keys stay plural — they switch a class of lines; each line is
one instance).

Claude-Session: https://claude.ai/code/session_014GN8u3zdH3RpeftHZChavP

Claude-Session: https://claude.ai/code/session_014GN8u3zdH3RpeftHZChavP

tool_call / tool_result (singular) everywhere: event types, text labels,
and now the config keys, which select event types by name.

Claude-Session: https://claude.ai/code/session_014GN8u3zdH3RpeftHZChavP

…r; stream docstring says show_process is on by default

- The managed endpoint reports a server-side failure as a final
  {"error": ...} chunk after the partial answer (api.py refunds the
  credits, then yields it). Neither chunk decoder looked at it, so
  chat(stream=True) and chat_completions(stream=True) in both modes
  ended as an apparently complete short answer with no exception. One
  guard in each decoder raises PageIndexAPIError; the partial answer
  is still delivered first.
- The `stream:` arg and the Returns block still described the pre-PR
  contract (bare text chunks); only the show_process paragraph said it
  is on by default.

Claude-Session: https://claude.ai/code/session_01PYr9yG1FPQxKCA9m7ECQWY

…nion

main's chat() returns a wider union (the protocol lanes), so the exact
comparison held only on this branch; membership is what the test is for.

Claude-Session: https://claude.ai/code/session_01PYr9yG1FPQxKCA9m7ECQWY

…commit