docs: RELEASES.md entry for 8.2.0 (temporal VFS)

RELEASES.md

@@ -10,6 +10,39 @@ Full auto-generated changelog: `CHANGELOG.md` · Releases: https://github.com/so
 
 ---
 
+## v8.2.0 — 2026-07-10 (temporal VFS — file content joins the immutability model)
+
+Time travel now covers Virtual Filesystem **content**. Previously the temporal model had a hole
+exactly where files were concerned: every entity write was an immutable generation, but the
+content *bytes* lived under an eager reference-count GC — deleting a file could physically destroy
+bytes that in-window history still referenced, while overwriting never released the old content at
+all (an unbounded silent leak that only *accidentally* preserved history). A production consumer's
+recovery from a bad deploy succeeded only because a stale field happened to hold the good value —
+luck, not a guarantee. Both directions are now fixed by making blob reclamation a **history**
+decision instead of a **liveness** decision:
+
+- **Content blobs are retention-protected.** Each blob tracks live references AND history
+  references (one per persisted generation record that carries its hash). Deleting/overwriting a
+  file drops only the live reference; bytes are physically reclaimed in exactly one place —
+  history compaction — once no live reference and no retained generation references the hash.
+  Pinned views are exempt automatically (compaction already respects pins). Crash ordering is
+  over-count-only (never under-count), so a crash can leak until the built-in scrub recounts, but
+  can never reclaim bytes history still needs. Existing stores get a one-time, marker-gated
+  backfill on open; cross-file content dedup is handled exactly.
+- **`vfs.readFile(path, { asOf })`** — the file's exact bytes as of a generation or `Date`,
+  guaranteed present within the retention window.
+- **`vfs.history(path)`** — the file's versions (`{ generation, timestamp, hash, size,
+  mimeType? }`, ascending). Restore = read the old bytes `asOf` and write them back (a new write;
+  history is never rewritten).
+- **Overwrites now refresh the file entity's `data`/embedding text** — previously semantic search
+  and the `data` field served the FIRST version's text forever.
+
+Lifecycle note: deleting a file no longer frees its bytes immediately — old content lives until
+compaction reclaims its generations, under the same `retention` budget as all Model-B history
+(`retention: 'all'` keeps every version forever). Guide: the new "Time travel for files" section in
+`docs/guides/snapshots-and-time-travel.md`. Native accelerator: unaffected (canonical write path
+only) — no version pairing required.
+
 ## v8.1.0 — 2026-07-10 (`brain.onChange` — the in-process change feed)
 
 New public API: subscribe to every committed mutation with