docs(planning): close Track A — A1 shipped v0.5.7, A2 shipped v0.6.2

BACKLOG audit found Track A's two items both already landed in
earlier releases:

- A1 (interpreter folder browser): shipped v0.5.7 as
  ``python_interpreter_browser.py`` + the "Browse remote
  filesystem..." quick-panel row. The "autocompletion as you type"
  piece is genuinely separate work and lives under W4.
- A2 (status-bar indicator): shipped v0.6.2 as ``Python: <venv>
  (<X.Y.Z>)`` with version probe + cache + syntax gating. M2 had
  the same done-when; both folded together.

Track A is now strikethrough'd / closed. Active queue narrows to
G (git/SCM) + M3 (extension install latency + auto-format race) +
W1/W4 (Windows parity). Track E stays as reference-only.

No code change needed; just BACKLOG hygiene. v0.7.8 release skipped
since there's nothing to ship — next user-visible version is
whatever lands first from G / M3 / W.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

planning/BACKLOG.md

@@ -8,20 +8,19 @@ Active tracks (2026-04-27 onward):
 
 - **G** — Sublime Merge–compatible git/SCM integration (the next big
   feature; v0 = single-repo MVP).
-- **A** — Python interpreter UX polish (small, sequential).
-- **M** — selected macOS follow-ups (M3 install latency, M4 plain-close
-  palette wiring, M5 remainder for non-mirror-sync timeouts).
-- **W** — Windows parity for the still-relevant items (W1
-  PersistentBroker, W4 folder browser auto-descend).
+- **M** — M3 (remote extension install/probe latency + auto-format race) is
+  the only macOS follow-up still open; M1/M2/M4/M5 shipped or retired.
+- **W** — Windows parity: W1 (PersistentBroker for LSP stdio multiplex)
+  and W4 (folder browser auto-descend on `/`).
 - **E** — security/ops, slower cadence; not on the active queue but
   retained for visibility.
 
-Dropped (2026-04-27): Track D (agent integration via tmux — agent now
-runs in an external terminal, no in-Sublime wiring), Track C (Terminus
-session persist + hover — terminal's role narrowed to "lightweight
-execution"; mirror items W2/W3 dropped for the same reason), Track B
-(extension probe caching merged into M3; Cargo.toml hydrate-on-demand
-deferred).
+Dropped / closed (2026-04-27): Track A closed (A1 shipped v0.5.7, A2
+shipped v0.6.2 — entries were stale). Track B dropped (B1 absorbed
+into M3, B2 deferred). Track C dropped (Terminus session persist +
+hover — terminal's role narrowed to "lightweight execution"; mirror
+items W2/W3 dropped for the same reason). Track D dropped (agent
+runs in an external terminal now, no in-Sublime wiring).
 
 Legend:
 
@@ -31,35 +30,25 @@ Legend:
 
 ---
 
-## Track A — Python interpreter UX polish
+## ~~Track A — Python interpreter UX polish~~ — **[shipped, closed 2026-04-27]**
 
-*Both tasks touch `python_interpreter_registry.py` +
-`commands.py::SessionsSelectPythonInterpreterCommand` area only. Pick
-one agent to drive the whole track sequentially; tasks are too small
-to parallelise internally but the track as a whole is independent.*
+Both items already landed in earlier releases; the track was kept
+open in BACKLOG by mistake.
 
-### A1. Remote folder browser for the interpreter picker
+### A1. Remote folder browser for the interpreter picker — **[shipped v0.5.7]**
 
-Currently the manual-entry option is a plain input panel. The user
-wants an "Open Folder" style browser with autocompletion as they type.
+`python_interpreter_browser.py` + the `Browse remote filesystem...`
+quick-panel row reach the documented done-when (navigate from
+`$HOME`, descend / ascend / select Python binary; selection writes
+via `write_active_interpreter`). The "type as you go" autocompletion
+piece overlaps with W4 (folder browser auto-descend on `/`); tracked
+there.
 
-- **[file]** `python_interpreter_registry.py`, `commands.py`
-- **[done-when]** Picking "Enter remote path manually…" opens a
-  navigable quick panel starting at `$HOME`. Each item is either a
-  subdirectory (descend), `..` (ascend), or an executable candidate
-  (`python`, `python3`). Typing filters the list. Selecting an
-  executable writes it via `write_active_interpreter`.
-- **[conflict with]** none.
+### A2. Status-bar indicator styling — **[shipped v0.6.2]**
 
-### A2. Status-bar indicator styling
-
-The `py: <short>` indicator is hard to spot in macOS ST4.
-
-- **[done-when]** Indicator reliably visible on every workspace view;
-  style (prefix, width, truncation rule) tuned by at least one macOS
-  test pass. Consider a fixed-width prefix like `● py:` so the eye
-  catches it.
-- **[file]** `commands.py::SessionsPythonInterpreterStatusListener`
+`Python: <venv> (<X.Y.Z>)` with version probe + cache, syntax-gated
+so non-Python views drop the slot. Same surface M2 was tracking —
+folded together at BACKLOG cleanup.
 
 ---