[CTX-0008] feat(storage): bounded snapshot component server (bitty#2495)

.github/workflows/ci.yml

@@ -37,3 +37,64 @@ jobs:
       - uses: docker://rhysd/actionlint:1.7.12@sha256:b1934ee5f1c509618f2508e6eb47ee0d3520686341fec936f3b79331f9315667
         with:
           args: -color
+  rust:
+    name: Rust quality gates (fmt, clippy, test)
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - name: Install Rust toolchain
+        uses: dtolnay/rust-toolchain@e2a55d2ffb04f378e9626c28d38b36d230d1e12f # v1
+        with:
+          toolchain: 1.98.1
+          components: rustfmt, clippy
+      - run: cargo fmt --all -- --check
+      - run: RUSTFLAGS="-D warnings" cargo clippy --workspace --all-targets
+      - run: cargo test --workspace --locked
+
+  component-package:
+    name: Component package (linux x86_64)
+    runs-on: ubuntu-24.04
+    timeout-minutes: 30
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - name: Install Rust toolchain
+        uses: dtolnay/rust-toolchain@e2a55d2ffb04f378e9626c28d38b36d230d1e12f # v1
+        with:
+          toolchain: 1.98.1
+      - name: Build release component
+        run: cargo build --release --locked --target x86_64-unknown-linux-gnu --bin bitty-storage
+      - name: Pack target archive and checksums
+        run: |
+          scripts/package-component.sh \
+            --version "$(sed -n 's/^version = "\(.*\)"$/\1/p' Cargo.toml | head -n 1)" \
+            --target x86_64-unknown-linux-gnu \
+            --binary target/x86_64-unknown-linux-gnu/release/bitty-storage \
+            --output dist/x86_64-unknown-linux-gnu.tar.gz
+      - name: Verify package shape
+        run: scripts/test-package-component.sh
+      - name: Smoke-test the packed executable
+        run: |
+          set -euo pipefail
+          version="$(sed -n 's/^version = "\(.*\)"$/\1/p' Cargo.toml | head -n 1)"
+          mkdir -p dist/smoke
+          tar -xzf dist/x86_64-unknown-linux-gnu.tar.gz -C dist/smoke
+          dist/smoke/bitty-storage --version | grep -Fx "bitty-storage $version"
+          dist/smoke/bitty-storage --check-manifest dist/smoke/bitty-component.toml
+          test -s dist/SHA256SUMS
+          (cd dist && sha256sum -c SHA256SUMS)
+      - name: Run the live protocol suite against the packed executable
+        env:
+          BITTY_STORAGE_COMPONENT_BIN: ${{ github.workspace }}/dist/smoke/bitty-storage
+        run: cargo test --test component_server --locked
+      - uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          name: storage-component-linux-x86_64
+          path: |
+            dist/*.tar.gz
+            dist/*.sha256
+            dist/SHA256SUMS
+          if-no-files-found: error
+          retention-days: 7

AGENTS.md

@@ -3,3 +3,5 @@
 Metadata-only candidate; no product migration authorized. Read repo.toml, TODO, CarryCtx and shared security corpus. W-131 must separate transcript, command history, session snapshots and sandboxed plugin KV. No generic database, arbitrary filesystem authority or default raw stdout persistence. Terminal Truth remains volatile and Core-owned. Require opt-in capture, isolation, retention/deletion, secret minimization, recovery and bounded schemas.
 
 English only; no hardcoded host values. Rust starts 0.0.1, edition 2024, Core MSRV. Run just gates; metadata checks are not product evidence. CTX-0001 -> 0002 -> 0003 -> 0004 orders bootstrap, contracts, implementation, independent verification. Named sessions, narrowed scopes, task worktrees after first commit; managed hooks required. Direct bootstrap is authorized, not independent acceptance. No commit/push/release without authority; publish redacted snapshots only. Preserve unrelated work; no silent installs, destructive cleanup or unowned process kills. Record negative tests and canonical docs synchronization.
+
+Executable component boundary (CTX-0008, bitty#2495): the `storage` component is a stdio coprocess around journaled namespaces, not a second database. Preserve protocol v1 framing and bounds, atomic journal-before-snapshot commits, previous-revision rollback semantics, and the rule that the wire carries namespaces/keys/values but never a filesystem path. The host chooses the root at spawn time and owns installation, digest verification, capability grants, consent, safe-mode denial, XDG migration, and restore re-derivation; the component commits exactly the batch it is handed. On Linux/Android state operations must stay directory-fd anchored (`openat`/`renameat`/`unlinkat`) with `O_NOFOLLOW` final components and `O_CREAT|O_EXCL` temps; never reintroduce path-based state access, symlink following, or a non-Linux fallback. Do not add an installer, download source, catalog row, or Core dependency here. `just component-package` builds and packs locally; no tag or R2 upload belongs to this task.

Cargo.toml

@@ -14,8 +14,18 @@ publish = false
 name = "bitty_storage"
 path = "src/lib.rs"
 
+[[bin]]
+name = "bitty-storage"
+path = "src/bin/bitty-storage.rs"
+
 [lints.rust]
 unsafe_code = "forbid"
 
 [lints.clippy]
 all = { level = "warn", priority = -1 }
+
+# Namespace locks are OS advisory `flock`s, safe API only (no `unsafe`).
+# Same platform split as the Core/execution claim lock; the Linux x86_64
+# component is the packaged target for this task.
+[target.'cfg(any(target_os = "linux", target_os = "android"))'.dependencies]
+rustix = { version = "1.1.4", default-features = false, features = ["fs", "std"] }