fix(recovery): resolve metadata MAC desync after recovery (R-NEW-1) & complete release workflow (CI-01)

- R-NEW-1: Recalculate metadata HMAC upon recovery-key restore and mark backup restores as PendingRebuild to rebuild transparently on first mount
- CI-01: Update release.yaml to compile both Windows x86_64 and Linux musl with pinned Zig 0.16.0 and cargo-zigbuild 0.23.4
- W-1: Implement statvfs quota determination on Unix via libc
- Add RELEASE_PROCESS.md documenting release architecture and steps
- Bump version to 0.9.2 across manifests, lockfile, docs, Scoop and WinGet

Cargo.lock

@@ -1457,7 +1457,7 @@ checksum = "cf54715a573b99ac80df0bc206da022bcd442c974952c7b9720069370852e21f"
 
 [[package]]
 name = "sanctum"
-version = "0.9.1"
+version = "0.9.2"
 dependencies = [
  "aes-gcm",
  "anyhow",
@@ -1473,6 +1473,7 @@ dependencies = [
  "http-body-util",
  "hyper",
  "hyper-util",
+ "libc",
  "lz4_flex",
  "minisign-verify",
  "rand",