feat(chat): show real-time AI thinking steps inline while chatting

[hazemadelkhalel]

Summary

• Replace side panel thinking details with inline accordion matching Attio's UX
• During streaming: show latest thinking step with shimmer animation, fading between steps
• After completion: collapsible "Thought for X seconds" with full timeline (reasoning + tool calls + Done marker)
• Add ap_update_thinking_status tool for AI to announce steps in real-time
• Tool calls render as compact pill cards with piece icons and expandable JSON viewer
• Track and persist thinkingDurationMs for accurate duration on reload
• Consolidate duplicated utilities (deriveToolStatus, extractToolOutputText, extractPieceNames) into chatPartUtils

Test plan

• Send a chat message that triggers tool calls — verify current step appears below "Thinking..." with shimmer
• After completion, verify "Thought for X seconds" label
• Click accordion to expand — verify full timeline with reasoning, thinking status, tool cards, and Done marker
• Verify tool cards show piece icons (Gmail, Slack, etc.) when pieces are involved
• Reload the page — verify historical conversations reconstruct the accordion correctly
• Verify old conversations without THINKING_STATUS parts render gracefully
• Verify side panel is gone, bottom bar always visible

[greptile-apps]

Confidence Score: 4/5

The chat feature's logic changes are well-contained and backwards-compatible; the main gap is that the feature documentation was not updated to reflect the deleted panel, removed store state, and new thinking tool.

The code changes themselves are clean and additive — new part type, new tool, inline UI replacing the old side panel — and historical conversations reconstruct correctly. The missing update to .agents/features/chat.md is the only blocking gap: the doc still references the deleted thinking-details-panel.tsx, the old thinking panel store state, and omits ap_update_thinking_status from the tool inventory.

packages/web/src/app/routes/chat-with-ai/components/activity-accordion.tsx has the most new logic (streaming step renderer, tool cards, duration label) and warrants a careful manual test. The feature doc .agents/features/chat.md needs updating before merge.

Important Files Changed

Filename	Overview
packages/web/src/app/routes/chat-with-ai/components/activity-accordion.tsx	Major rewrite replacing the old simple button with a full inline accordion showing streaming thinking steps, a Done marker, and expandable tool cards with piece icons and JSON viewers.
packages/shared/src/lib/ee/chat/index.ts	Adds THINKING_STATUS part type with Zod schema, thinkingDurationMs optional field on messages, and ap_update_thinking_status to ChatToolOutputs; all are additive/backwards-compatible.
packages/web/src/features/chat/lib/chat-types.ts	Adds ThinkingStep union type, ToolStatus, isThinkingStatusTool, and consolidates deriveToolStatus/extractToolOutputText/extractPieceNames into chatPartUtils.
packages/web/src/features/chat/lib/chat-utils.ts	Adds THINKING_STATUS case in persistedPartToUIPart, reconstructing it as a synthetic dynamic-tool part with a part-index-based toolCallId; correctly spreads thinkingDurationMs onto historical messages.
packages/server/worker/src/lib/execute/jobs/ee/chat/execute-chat-agent.ts	Captures thinkingStartTime before streaming and attaches thinkingDurationMs to both in-progress and final saves; correctly includes thinkingTools in the tool set.
packages/web/src/app/routes/chat-with-ai/ai-chat-box.tsx	Removes the side-panel ThinkingDetailsPanel and the conditional AnimatePresence toggle; ChatBottomBar is now always rendered unconditionally.
packages/web/src/features/chat/lib/chat-store.ts	Removes thinkingPanelMessageId state and openThinkingDetails/closeThinkingPanel actions, which are no longer needed with inline thinking steps.

_{Reviews (2): Last reviewed commit: "fix(chat): resolve PR review comments" | Re-trigger Greptile}