[FEATURE] Living, auto-updated project narrative spanning all sessions in a repo

Summary

There's no single, auto-updated "story so far" for a project that spans all sessions ever run against it — only per-session transcripts and (per #11455) a proposed next-session handoff note. Please add a living, continuously updated project narrative that accumulates across a repo's entire history of Claude Code sessions, not just a bridge to the next one.

Current behavior

Project history currently lives as a collection of discrete session transcripts plus whatever the user or CLAUDE.md manually records. There's no single document that reads like an ongoing narrative — "here's what's happened in this project across every session" — that a new session (or the user themselves) could consult to understand the arc of a project without either re-reading many individual transcripts or relying on a single handoff note scoped to just the most recent session.

Motivation

This is cited as a specific competitive differentiator in the market: comparison pieces (CodeAnt/Kanerika, 2026) describe Windsurf's "Cascade Flows" as maintaining a persistent running narrative of work across a project, contrasted with tools that reconstruct context fresh each time. For a project actively worked on across weeks or months and many separate sessions, a per-session or per-handoff view is a much thinner form of continuity than an accumulating narrative of the project's actual arc — decisions made, why, what was tried and abandoned, what's currently in flight.

Proposed behavior

1. A per-project narrative document, automatically appended to (not manually maintained) as sessions complete — a running summary distinct from both raw transcripts and the single-handoff concept in #11455.
2. Summarizes at a higher level than a session-by-session log: key decisions, direction changes, abandoned approaches and why, current state — the kind of thing a human would want to read to get oriented on a project they haven't touched in a while.
3. Should be readable/browsable on its own (not just silently injected into context), so the user can also use it as a project log, and editable so incorrect auto-summarization can be corrected.

Why it matters

• Gives real continuity for long-running projects touched across many separate sessions over weeks/months, which is a common usage shape (see #79086, #79087 context on juggling many concurrent projects) — closing a gap between "one next-session note" and "full transcript archaeology."
• Matches an explicitly named competitive differentiator rather than a purely speculative ask.

Related issues (adjacent, not duplicates)

• #11455 Feature Request: Session Handoff / Continuity Support — closely related but narrower: that proposes a single .claude/handoff.md bridging to the next session; this request is for an accumulating narrative across all sessions over the project's whole history, more akin to a living project log than a one-hop handoff.

Notes

• Reviewed for duplicates before filing (multiple search passes: "living project narrative document spanning all sessions repo story so far", "project timeline summary across sessions changelog", "running summary of everything done in this repo") — the only closely related result is #11455, distinct enough (single-hop handoff vs. full accumulating narrative) to file separately, but should probably be considered together with it during design if both move forward.
• Sourced from market research: CodeAnt/Kanerika 2026 comparison articles citing Windsurf Cascade's persistent-narrative UX as a named differentiator.