hive-agent: warn + emit an OTEL gauge on a grown CLAUDE.md

hive-agent/src/otel_turn_metrics.rs

@@ -18,6 +18,11 @@
 //! from `handle_turn`. The `PeriodicReader` still batches + exports on its
 //! own interval; only the recording is event-driven, not the export.
 //!
+//! [`record_claude_md_lines`] is the one exception, sharing this module's
+//! exporter setup rather than [`record`]'s per-turn call site — `CLAUDE.md`
+//! size *is* continuously live (like hive-c0re's cgroup values), so
+//! [`crate::claude_md_watch`] records it from its own periodic tick instead.
+//!
 //! Resource attributes (`service.name`, `agent`, `hive`, `swarm`) are picked
 //! up automatically by the SDK from the container-wide `OTEL_RESOURCE_ATTRIBUTES`
 //! env var (same mechanism `hive-metric` relies on) — nothing to set here.
@@ -46,6 +51,11 @@ struct Instruments {
     session_count: Counter<u64>,
     open_threads: Gauge<u64>,
     open_reminders: Gauge<u64>,
+    /// Recorded from [`crate::claude_md_watch`]'s own tick, not from
+    /// [`record`] — `CLAUDE.md` size is a continuously-live value (like
+    /// hive-c0re's container gauges), not a once-per-turn one, so it has
+    /// its own entry point rather than riding `record`'s per-turn call.
+    claude_md_lines: Gauge<u64>,
 }
 
 /// Lazily built on the first call to [`record`]. `None` when OTEL isn't
@@ -87,6 +97,18 @@ pub fn record(row: &TurnStatRow, fresh_session: bool) {
     }
 }
 
+/// Record the current `CLAUDE.md` line count. Called from
+/// [`crate::claude_md_watch`]'s periodic tick (every ~15 minutes, not
+/// per turn) — see the field doc on [`Instruments::claude_md_lines`] for
+/// why this doesn't ride [`record`]. No-op when OTEL isn't configured,
+/// same as `record`.
+pub fn record_claude_md_lines(lines: u64) {
+    let Some(inst) = INSTRUMENTS.get_or_init(build).as_ref() else {
+        return;
+    };
+    inst.claude_md_lines.record(lines, &[]);
+}
+
 fn build() -> Option<Instruments> {
     if !enabled() {
         tracing::debug!("otel turn-metrics: no endpoint configured, exporter disabled");
@@ -110,6 +132,7 @@ fn build() -> Option<Instruments> {
                 open_reminders: meter
                     .u64_gauge("hyperhive.agent.loose_ends.reminders")
                     .build(),
+                claude_md_lines: meter.u64_gauge("hyperhive.agent.claude_md.lines").build(),
                 _provider: provider,
             })
         }