Plan M5a: local memory in 15 tasks

memoryd (files, the check, edits, journal, index, recall, serving),
the memory tools and built-in grants in brokerd, the memory block in
loopd, bxctl reindex and memory, and the device checks with memoryd.

Each task was built as a reference and gated. Each was replayed on its
own at its end state (854 to 936 tests) and mutation-checked. Each
skeleton compiles and fails its tests. Every todo comment was read
beside its signature.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

docs/plans/M5a/files/crates/memoryd/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "memoryd"
+version = "0.1.0"
+edition.workspace = true
+rust-version.workspace = true
+publish.workspace = true
+
+[lints]
+workspace = true
+
+[dependencies]
+proto.workspace = true
+rusqlite.workspace = true
+serde.workspace = true
+serde_json.workspace = true
+toml.workspace = true