docs: sweep sync follow-ups into their owning version docs

Kaizen/postmortem next-steps kept accumulating with no owner. Each item
now lives in one version doc (v0.7 sync perf, v0.9 robustness, v1.0
boot) with the source docs linking there; the editor-freeze safety net
is marked hardware-verified and the v0.5 walk re-measure closed at 4.3s.

docs/v0.9-robustness.md

@@ -5,8 +5,22 @@
 
 **Status:** not started.
 
-- [ ] Crash-safe writes (write to `.tmp`, fsync, rename)
-- [ ] Recover from interrupted push (re-attempt on next save)
+- [ ] Crash-safe writes (write to `.tmp`, fsync, rename) — NB FatFS `f_rename`
+      refuses to overwrite, so it's unlink-then-rename + `*.tmp` boot-recovery
+      (found in [Spike 3](postmortems/2026-07-05-spike3-sd-cmd59.md), still
+      open there)
+- [ ] Recover from interrupted push (re-attempt on next save) — the splice
+      journal + stranded-commit recovery (2026-07-13) already survive a
+      power-pull mid-push; this item is the *retry* half
+- [ ] Reconnect-on-stale-connection in the libgit2 http/stream layer — the
+      push keep-alive race is **avoided, not fixed** (repack keeps the marking
+      phase at ~3.5 s ≪ the ~30 s idle window; a multi-pack or cold-cache
+      state could still lose it — see the
+      [real-repo-sync kaizen](kaizen/real-repo-sync.md))
+- [ ] Eradicate the paint-during-sync DMA allocation failure: persistent
+      internal DMA scratch in `Epd` (safety net + allocation-free repaints
+      shipped; see the
+      [editor-freeze postmortem](postmortems/2026-07-11-editor-freeze-spi-dma-oom-during-sync.md))
 - [ ] SD card removal / reinsert handling
 - [ ] Wi-Fi reconnect with backoff
 - [ ] On-device provisioning + settings screen: SSID, PAT rotation, default