feat(agent-tools): handle tool rejection and approval states

[wsp1911]

Summary

Adds structured handling for agent tool rejection, confirmation timeout, and execution timeout states across the Rust tool pipeline and FlowChat UI.

Fixes #

Type and Areas

Type:

Feature / UI/UX / test

Areas:

Rust core, execution tool contracts, agent runtime, CLI, web UI, i18n

Motivation / Impact

Previously, user-rejected tool calls and confirmation / execution timeouts could surface as generic failures or argument errors. This change returns structured tool results for those cases so the assistant receives clearer guidance and avoids blindly retrying rejected or timed-out tool calls.

For users, FlowChat now shows an approval bar with approve, reject, reject-with-instruction, permission options, and a countdown when a confirmation timeout is available. Rejected tool calls render as a distinct state across tool cards instead of being folded into generic cancelled/error handling.

This also keeps CLI handling compatible with the expanded confirmation-needed event payload.

Verification

Passed:

• pnpm run fmt:rs
• pnpm run type-check:web
• pnpm run i18n:audit
• cargo check --workspace
• cargo test -p bitfun-agent-tools --test tool_contracts
  • 88 passed
• cargo test -p bitfun-agent-runtime --test tool_confirmation_contracts
  • 4 passed
• cargo test -p tool-runtime --test tool_pipeline_planning
  • 8 passed
• cargo test -p bitfun-core confirmation_rejection_returns_user_rejected_result_without_argument_error
  • 1 passed
• cargo test -p bitfun-core confirmation_timeout_returns_timeout_result_without_argument_error
  • 1 passed
• pnpm --dir src/web-ui run test:run src/flow_chat/components/ToolApprovalBar.test.tsx src/flow_chat/tool-cards/ExecProcessToolCardView.test.tsx src/flow_chat/services/flow-chat-manager/ToolEventModule.test.ts src/flow_chat/tool-cards/ReadFileDisplay.test.tsx
  • 4 test files passed, 18 tests passed

Reviewer Notes

The PR adds a new Rejected tool state/event path and extends confirmation-needed events with timeout metadata. The CLI match path now ignores unknown/additional confirmation fields so it remains compatible with the expanded payload.

The FlowChat approval countdown test mock now performs basic i18n interpolation, which matches the component’s use of remaining {{time}}.

Checklist

• This PR is focused and does not include secrets, temporary prompts, generated scratch files, or unrelated artifacts.
• Relevant verification is recorded above, or skipped checks are explained.
• User-facing strings, docs, and locales are updated where applicable.