Move memory state to a dedicated SQLite DB (#24591)

## Summary

Generated memory rows and their stage-one/stage-two job state currently
live in `state_5.sqlite` alongside thread metadata. That makes memory
cleanup and regeneration share the main state schema even though those
rows are memory-pipeline data and can be rebuilt independently from the
durable thread records.

This PR moves the memory-owned tables into a dedicated
`memories_1.sqlite` runtime database while keeping thread metadata in
`state_5.sqlite`.

## Changes

- Adds a separate memories DB runtime, migrator, path helpers, telemetry
kind, and Bazel compile data for `state/memory_migrations`.
- Introduces `MemoryStore` behind `StateRuntime::memories()` and moves
memory table/job operations onto that store.
- Drops the old memory tables from the state DB and recreates their
schema in `state/memory_migrations/0001_memories.sql`.
- Updates memory startup, citation usage tracking, rollout pollution
handling, `debug clear-memories`, and app-server `memory/reset` to
operate through the memories DB.
- Preserves cross-DB behavior by hydrating thread metadata from the
state DB when selecting visible memory outputs and checking stage-one
staleness.

## Verification

- Added/updated `codex-state` tests for deleted-thread memory visibility
and already-polluted phase-two enqueue behavior.
- Updated `debug clear-memories`, app-server `memory/reset`, and
memories startup tests to seed and assert memory rows through
`memories_1.sqlite`.

codex-rs/cli/src/doctor/output.rs

@@ -702,6 +702,7 @@ fn state_summary(check: &DoctorCheck) -> String {
         "state DB integrity",
         "log DB integrity",
         "goals DB integrity",
+        "memories DB integrity",
     ]
     .into_iter()
     .all(|label| detail::detail_value(check, label).is_some_and(|value| value == "ok"));
@@ -1363,6 +1364,37 @@ Run codex doctor without --summary for detailed diagnostics.
         );
     }
 
+    #[test]
+    fn render_human_report_includes_memories_db_in_state_health_summary() {
+        let report = DoctorReport {
+            schema_version: 1,
+            generated_at: "0s since unix epoch".to_string(),
+            overall_status: CheckStatus::Ok,
+            codex_version: "0.0.0".to_string(),
+            checks: vec![
+                DoctorCheck::new(
+                    "state.paths",
+                    "state",
+                    CheckStatus::Ok,
+                    "state paths inspectable",
+                )
+                .detail("state DB: /tmp/state.sqlite")
+                .detail("state DB integrity: ok")
+                .detail("log DB: /tmp/logs.sqlite")
+                .detail("log DB integrity: ok")
+                .detail("goals DB: /tmp/goals.sqlite")
+                .detail("goals DB integrity: ok")
+                .detail("memories DB: /tmp/memories.sqlite")
+                .detail("memories DB integrity: ok"),
+            ],
+        };
+
+        let rendered = render_human_report(&report, detailed_no_color_unicode_options());
+
+        assert!(rendered.contains("✓ state        databases healthy"));
+        assert!(rendered.contains("memories DB              /tmp/memories.sqlite · integrity ok"));
+    }
+
     #[test]
     fn render_human_report_supports_ascii_output() {
         let rendered = render_human_report(

codex-rs/cli/src/doctor/output/detail.rs

@@ -413,6 +413,7 @@ fn state_details(parsed: &[ParsedDetail]) -> Vec<HumanDetail> {
     push_database_row(&mut out, parsed, "state DB");
     push_database_row(&mut out, parsed, "log DB");
     push_database_row(&mut out, parsed, "goals DB");
+    push_database_row(&mut out, parsed, "memories DB");
 
     for (source, label) in [
         ("active rollout files", "active rollouts"),
@@ -440,6 +441,8 @@ fn state_details(parsed: &[ParsedDetail]) -> Vec<HumanDetail> {
             "state DB integrity",
             "log DB integrity",
             "goals DB integrity",
+            "memories DB",
+            "memories DB integrity",
             "active rollout files",
             "archived rollout files",
         ],