Task: Diagnose older conversation history loading

Identity

Task ID: 20260831-diagnose-history-pagination-3eac1d7b
Mode: Feature
Branch: codex/20260831-diagnose-history-pagination-3eac1d7b-diagnose-history-pagination-3eac1d7b
Worktree: /Users/inmanx/Documents/makelore-diagnose-history-pagination-3eac1d7b
Base commit: 38f85f6b5e
Owner: codex
Status: Ready for Integration

Diagnose why older messages stop loading while scrolling upward in the Makelore Code conversation shown in the supplied screenshot.
Trace Renderer scroll behavior, the public Snapshot/Host API contract, Main-owned Pi session hydration, and the persisted session data for the affected local conversation.
Make no product-source, dependency, runtime, account, or external-service changes.

Preserve the Main-owned Pi 0.84.2 and product-neutral Snapshot/Patch boundary; do not introduce or infer a Renderer-to-Pi history path.
Treat the running development worktree, application logs, project metadata, and Pi session files as read-only evidence.
Distinguish persisted-data loss from a bounded projection or missing UI/API pagination mechanism.

Identified a deterministic two-layer history-display boundary rather than a transport stall or corrupt session.
The affected Pi JSONL remains intact at 343 records / 782,976 bytes. Its active branch contains 342 entries from 2026-08-28T08:34:53Z through 2026-08-31T11:25:59Z, with all parent links traversable to the current leaf.
The branch contains one compaction. projectPiSessionSnapshot() calls retainedTail(), which intentionally discards every active-path entry before the compaction's firstKeptEntryId. For this session that hides 136 records, including 128 raw messages and approximately 131 product timeline nodes. The first retained record begins at 2026-08-29T06:11:52Z.
The remaining tail projects to approximately 195 timeline nodes. Renderer shows the newest 120 nodes and the 加载更早内容 button only increases that in-memory window by 100. Its scroll handler merely tracks stick-to-bottom; it does not request older history.
The public Snapshot contract and /snapshot route expose no history-page cursor or before parameter. After the one in-memory expansion reaches all 195 projected nodes, no additional Main/Pi request is possible even though the omitted records are still on disk.
No product source, dependencies, runtime, account, session, or external service were changed.

Parsed the affected .makelore/conversations.json binding and its exact managed Pi JSONL without writing either file.
Counted JSONL record types, reconstructed the current leaf-to-root active path, checked the compaction boundary, and counted retained versus omitted messages/product nodes.
Inspected CodingConversationTimeline, the Renderer conversation Store, shared Snapshot contract, Coding Host route, Pi runtime hydration, session-projector, and Agent Server get_entries behavior.
Confirmed current unit coverage explicitly expects pre-firstKeptEntryId history to be absent and covers only in-memory window expansion.
Searched the current Main log and found no CODING_SESSION_UNREADABLE, missing-entry, or history-load error for this incident.
No tests were run because this was a read-only diagnosis with no behavior change; the isolated worktree has no installed node_modules.

If a fix is requested, keep the full active-branch history available for UI display independently of the compacted model-context tail. Add a bounded older-history cursor/route (or, as a minimal correction, project the full active path) and make Renderer prepend pages while preserving the scroll anchor. Keep the compaction summary private and retain Snapshot/Patch as the product-neutral boundary.