* fix: capacity-aware tool output truncation and context overflow recovery
Large tool results (e.g. 593K-char search output) could overflow the
context window in a single turn when the conversation was already
partially full. The fixed 50%-of-context truncation limit didn't
account for current usage.
Changes:
- _truncate_output() now accepts remaining token budget and uses
min(tool_truncation, remaining_budget_chars) as the effective limit
- _remaining_token_budget() helper calculates available capacity with
reserves for max_tokens response and 5% safety margin
- Safety truncation at tool-result append: every string tool result is
clamped to remaining budget before entering the message array
- _exec_web_search() now calls _truncate_output() (was missing)
- Context overflow recovery: catches provider errors indicating context
length exceeded (OpenAI + Anthropic patterns), auto-compacts, retries
once. Falls back to original error if compact-and-retry fails.
* fix: address review — zero-budget floor, nested spinner, Anthropic patterns, tests
- Remove 256-char floor from budget truncation — zero budget now returns
a placeholder instead of allowing 256 chars through
- Stop thinking spinner before compact to avoid nested start/stop
- Add Anthropic error patterns (prompt is too long, input tokens)
- Wrap compact-and-retry so failures re-raise the original error
- Add 15 tests covering budget calculation, capacity-aware truncation,
and overflow recovery for both providers
* fix: cap response reservation at 25% of context window
Reserving the full max_tokens in _remaining_token_budget() zeroed the
budget for common configs like max_tokens=32768 on a 32K context,
collapsing all tool output to a placeholder. max_tokens is a ceiling,
not guaranteed consumption — cap the reserve at context_window // 4.
Adds regression test for max_tokens >= context_window.
Patrick Buckley
d100ac92d9