docs(working): add a human-facing index + plan status reference

CLAUDE.md keeps the status convention as a one-line rule (it has to be
loaded to be followed). This is the same convention written out for a
human reader, with the meanings the trim dropped, plus what each
subfolder of docs/working/ is for and a grep one-liner for "what's open".

Notes the two distinctions that matter in practice: Deferred is not
Abandoned, and a trailing note after "Complete" is normal.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

docs/README.md

@@ -8,7 +8,7 @@
 - [Switching to a new trip](guides/trip-switching.md)
 - [Rebuilding local dev from scratch](guides/local-setup.md)
 
-**Checking project status?** → [`working/`](working/)
+**Checking project status?** → [`working/`](working/) — [what's in there + the plan status convention](working/README.md)
 - [Backlog](working/backlog.md)
 - [Bugs and fixes](working/bugs-and-fixes.md)
 - [QA results](working/qa/results.md)

docs/working/README.md

@@ -0,0 +1,52 @@
+# docs/working/ — work in flight
+
+Everything here is a live working document: specs being built from, plans being executed, notes from sessions in progress. Once something is finished it stays (as a record) rather than being deleted — the `**Status:**` line is how you tell the difference.
+
+Stable facts belong in [`../reference/`](../reference/); how-to procedures in [`../guides/`](../guides/); write-ups of bugs already solved in [`../solutions/`](../solutions/).
+
+---
+
+## What's in here
+
+| Path | Contents |
+|---|---|
+| `specs/` | Design docs — the *what* and *why*, written before a plan. Named `YYYY-MM-DD-<topic>-design.md` |
+| `plans/` | Implementation plans — the ordered *how*, with a status line. Named `YYYY-MM-DD-<topic>.md` |
+| `milestones/` | Milestone scope documents (`milestone-1.md` … ) |
+| `qa/` | Test plans, QA results, readiness audits |
+| `handovers/` | Session handover notes — context for picking up unfinished work |
+| `learnings/` | Retrospective notes worth keeping but not yet promoted to `../solutions/` |
+| `backlog.md` | Unscheduled ideas and wishes |
+| `bugs-and-fixes.md` | Running log of bugs found and what fixed them |
+| `summary.md` | Project summary / current state |
+| `pm-analysis.md`, `git-sync-notes.md`, dated one-offs | Standalone notes, kept for reference |
+
+---
+
+## Plan status convention
+
+Every plan in `plans/` carries a `**Status:**` line immediately after its title heading. This is the single place a plan's state is recorded — there is no separate tracker.
+
+| Status | Meaning |
+|---|---|
+| `📋 Not started` | Plan written and reviewed; no work begun yet |
+| `🔄 In progress — <note>` | Actively being worked on. The note says where it stopped, so anyone (or any session) can resume |
+| `⏸️ Deferred — <reason>` | Intentionally postponed. Still valid, just not now — the reason matters more than the status |
+| `✅ Complete (YYYY-MM-DD)` | Done and shipped. The date is when it landed, not when the plan was written |
+| `❌ Abandoned — <reason>` | Won't be implemented. Kept so the decision (and its reasoning) is not re-litigated later |
+
+Notes on using it:
+
+- **A trailing note after `✅ Complete` is normal and encouraged** for anything non-trivial — what actually shipped, what was deferred, which commit or environment it landed in. Several plans here carry a paragraph.
+- **`Deferred` is not `Abandoned`.** Deferred means "still want this"; abandoned means "decided against it". Keeping them distinct is the whole point of having both.
+- **Update the status when the work lands**, not later. A plan whose status lags reality is worse than no plan, because it is trusted.
+
+### Asking Claude what's open
+
+Claude reads these statuses directly (the convention is also in [`../../CLAUDE.md`](../../CLAUDE.md), so it applies without being asked). When asked what's open it will surface `Not started` and `In progress`, show `Deferred` items with the label made explicit, and leave out `Complete` and `Abandoned` unless you ask for them. It sets the status to `✅ Complete (YYYY-MM-DD)` on finishing a plan.
+
+A quick manual sweep of the same thing:
+
+```bash
+grep -rH '^\*\*Status:\*\*' docs/working/plans/ | grep -v 'Complete\|Abandoned'
+```