feat: add debug clear-memories command to hard-wipe memories state (#13085)

#### what
adds a `codex debug clear-memories` command to help with clearing all
memories state from disk, sqlite db, and marking threads as
`memory_mode=disabled` so they don't get resummarized when the
`memories` feature is re-enabled.

#### tests
add tests

codex-rs/cli/Cargo.toml

@@ -35,6 +35,7 @@ codex-mcp-server = { workspace = true }
 codex-protocol = { workspace = true }
 codex-responses-api-proxy = { workspace = true }
 codex-rmcp-client = { workspace = true }
+codex-state = { workspace = true }
 codex-stdio-to-uds = { workspace = true }
 codex-tui = { workspace = true }
 libc = { workspace = true }
@@ -62,3 +63,4 @@ assert_matches = { workspace = true }
 codex-utils-cargo-bin = { workspace = true }
 predicates = { workspace = true }
 pretty_assertions = { workspace = true }
+sqlx = { workspace = true }