compact: 閾値を個別指定化し占有量ソースを UsageRecord に一本化

- manifest に compact_request_threshold を追加 (proactive と safety net を個別指定)
- CompactState の両閾値を Option<u64> 化、last_input_tokens を撤去
- 閾値判定は Pod::total_tokens() / usage_history 経由の実測値ベースに切替
- turn_threshold → request_threshold にリネーム、Between-requests のログへ

crates/manifest/src/config.rs

@@ -84,6 +84,8 @@ pub struct CompactionConfigPartial {
     #[serde(default)]
     pub compact_threshold: Option<u64>,
     #[serde(default)]
+    pub compact_request_threshold: Option<u64>,
+    #[serde(default)]
     pub compact_retained_turns: Option<usize>,
     #[serde(default)]
     pub provider: Option<ProviderConfigPartial>,
@@ -236,6 +238,9 @@ impl CompactionConfigPartial {
             prune_protected_turns: upper.prune_protected_turns.or(self.prune_protected_turns),
             prune_min_savings: upper.prune_min_savings.or(self.prune_min_savings),
             compact_threshold: upper.compact_threshold.or(self.compact_threshold),
+            compact_request_threshold: upper
+                .compact_request_threshold
+                .or(self.compact_request_threshold),
             compact_retained_turns: upper
                 .compact_retained_turns
                 .or(self.compact_retained_turns),
@@ -365,6 +370,7 @@ impl TryFrom<PodManifestConfig> for PodManifest {
                         .prune_min_savings
                         .unwrap_or(defaults::PRUNE_MIN_SAVINGS),
                     compact_threshold: c.compact_threshold,
+                    compact_request_threshold: c.compact_request_threshold,
                     compact_retained_turns: c
                         .compact_retained_turns
                         .unwrap_or(defaults::COMPACT_RETAINED_TURNS),

crates/manifest/src/lib.rs

@@ -174,10 +174,27 @@ pub struct CompactionConfig {
     #[serde(default = "default_prune_min_savings")]
     pub prune_min_savings: u64,
 
-    /// When `input_tokens` exceeds this, run compact. `None` = compact disabled.
+    /// Proactive (between-turns) compaction threshold.
+    ///
+    /// Checked by the Controller after each run. When current occupancy
+    /// exceeds this value, compact runs before the next turn. `None`
+    /// disables the between-turns check.
     #[serde(default)]
     pub compact_threshold: Option<u64>,
 
+    /// Safety-net (between-requests) compaction threshold.
+    ///
+    /// Checked by `PodInterceptor::pre_llm_request` inside a turn. When
+    /// current occupancy exceeds this value, the run yields so that the
+    /// Controller can compact before the next LLM request. `None`
+    /// disables the between-requests check.
+    ///
+    /// Expected relation: `compact_threshold < compact_request_threshold`
+    /// (proactive triggers before safety net). A reversed configuration
+    /// is accepted but logged as a warning.
+    #[serde(default)]
+    pub compact_request_threshold: Option<u64>,
+
     /// Number of recent turns retained after compaction.
     #[serde(default = "default_compact_retained_turns")]
     pub compact_retained_turns: usize,
@@ -204,6 +221,7 @@ impl Default for CompactionConfig {
             prune_protected_turns: default_prune_protected_turns(),
             prune_min_savings: default_prune_min_savings(),
             compact_threshold: None,
+            compact_request_threshold: None,
             compact_retained_turns: default_compact_retained_turns(),
             provider: None,
         }
@@ -338,9 +356,37 @@ model = "claude-sonnet-4-20250514"
         assert_eq!(c.prune_protected_turns, 3);
         assert_eq!(c.prune_min_savings, 4096);
         assert_eq!(c.compact_threshold, Some(80000));
+        assert_eq!(c.compact_request_threshold, None);
         assert_eq!(c.compact_retained_turns, 2);
     }
 
+    #[test]
+    fn parse_compaction_both_thresholds() {
+        let toml = format!(
+            "{MINIMAL_REQUIRED}\n\
+             [compaction]\n\
+             compact_threshold = 80000\n\
+             compact_request_threshold = 90000\n"
+        );
+        let manifest = PodManifest::from_toml(&toml).unwrap();
+        let c = manifest.compaction.unwrap();
+        assert_eq!(c.compact_threshold, Some(80000));
+        assert_eq!(c.compact_request_threshold, Some(90000));
+    }
+
+    #[test]
+    fn parse_compaction_request_threshold_only() {
+        let toml = format!(
+            "{MINIMAL_REQUIRED}\n\
+             [compaction]\n\
+             compact_request_threshold = 90000\n"
+        );
+        let manifest = PodManifest::from_toml(&toml).unwrap();
+        let c = manifest.compaction.unwrap();
+        assert_eq!(c.compact_threshold, None);
+        assert_eq!(c.compact_request_threshold, Some(90000));
+    }
+
     #[test]
     fn parse_compaction_with_provider() {
         let toml = format!(