docs: archive the memory write-path audit

docs/tasks/archive/README.md

@@ -31,6 +31,10 @@ that owns its subject. Four live ones were promoted to `docs/` instead, as
 `FIRST-CLASS-APPS.md`, `SHELL-ECOSYSTEM.md`, `SETTINGS-AUTHORITY.md` and
 `AUDIO-PRIVACY.md`.
 
+The substrate memory write-path audit joined this archive on 2026-08-07 after
+the stale-index, delete, recursive status and sync paths were fixed and proved
+by Gitea run 1246.
+
 ## TASK-26 was never written and no longer needs to be
 
 It had two subjects and both closed. `blueline-proximity-lock` as a second

docs/tasks/archive/from-substrate/souveraine-memory-write-path-audit.md

@@ -0,0 +1,67 @@
+---
+task_id: souveraine-memory-write-path-audit-001
+title: "Memory writes must persist the git index"
+status: landed
+priority: high
+phase: memory
+created: 2026-08-07
+landed: 2026-08-07
+implementation: souveraine 0c9db09, 9ceaf61
+verification: Gitea Actions run 1246
+---
+
+# Memory write-path audit
+
+## Outcome
+
+Confirmed. The failure had four parts:
+
+1. `init()` staged its two seed files and wrote a tree, but never persisted
+   `.git/index`.
+2. `commit()` did the same after every `add_path()`.
+3. `delete()` unlinked the file and called `commit()`, whose absent-path case
+   staged nothing. There was no `remove_path()` anywhere in the module.
+4. `status()` did not read the index. It counted only root-level Markdown on
+   disk, while memory lives in nested directories. That was the independent
+   `Files: 0` bug.
+
+`sync()` was innocent: it pushes `HEAD` exactly, including a malformed tree.
+
+The frontmatter YAML issue is separate and was not changed here.
+
+## Reproduction found on disk
+
+The original report was exact:
+
+| Commit | Tree change |
+|--------|-------------|
+| `f3d80cb` | added `system/projects/souveraineos.md` |
+| `c60fbf4` | added `journal/2026-08-06.md` and silently deleted `souveraineos.md` |
+
+Both files remained in the working tree. The affected repository is
+`~/.souveraine/agents/99dd3a18-3e43-4160-9eec-b2ddb2b2a751/memory`.
+It was audited read-only; its unrelated dirty state was not reconciled by this
+task.
+
+## Landed repair
+
+- Persist the initial index before the initial tree is committed.
+- Base every later path-scoped commit on `HEAD`. This makes the repair safe for
+  legacy repositories whose index was already stale, without committing other
+  working-tree files.
+- Stage missing requested paths with `remove_path()`.
+- Persist the index before writing the commit tree.
+- Count Markdown recursively from disk for status.
+
+## Pipeline proof
+
+Gitea run 1246's `rust-test` job passed all named regressions:
+
+- `consecutive_writes_survive_in_head_and_index`
+- `next_write_repairs_a_legacy_stale_index`
+- `delete_survives_in_head_and_index`
+- `sync_pushes_instance_branch_to_bare_remote`
+
+The main suite reported 309 passed and 0 failed. No local build was substituted
+for the pipeline.
+