fix(acp): periodically reconcile channel membership

crates/buzz-acp/README.md

@@ -113,6 +113,7 @@ All configuration is via environment variables (or CLI flags — every env var h
 | `BUZZ_ACP_MCP_COMMAND` | no | `""` (empty) | Path to an optional MCP server binary to provide to the agent subprocess. |
 | `BUZZ_ACP_IDLE_TIMEOUT` | no | `620` | Idle timeout: max seconds of silence before cancelling a turn. Resets on any agent stdout activity. |
 | `BUZZ_ACP_MAX_TURN_DURATION` | no | `7200` | Absolute wall-clock cap per turn (safety valve). |
+| `BUZZ_ACP_CHANNEL_DISCOVERY_REFRESH_SECS` | no | `90` | Safety reconciliation interval for missed channel joins/removals. `0` disables; live membership notifications remain active. |
 | `BUZZ_API_TOKEN` | no | — | API token (required if relay enforces token auth). |
 
 **Note:** `BUZZ_ACP_AGENT_ARGS` splits on commas. For args with values, use: `-c,key="value"`.

crates/buzz-acp/src/config.rs

@@ -35,6 +35,18 @@ pub(crate) const DEFAULT_MAX_TURN_DURATION_SECS: u64 = 7200;
 /// deadline (`max_turn_duration + IN_FLIGHT_DEADLINE_BUFFER_SECS`).
 pub(crate) const MAX_TURN_DURATION_CEILING_SECS: u64 = 604_800;
 
+/// Default interval (seconds) between periodic channel re-discovery sweeps.
+///
+/// The live kind:44100 member-added notification is the primary subscribe
+/// trigger for newly joined channels. Notifications can still be missed during
+/// outages, backpressure, or compatibility with older relay/writer versions;
+/// the periodic sweep re-runs startup discovery so a running agent converges.
+/// Removals require two consecutive successful sweeps before cleanup.
+///
+/// Override via `--channel-discovery-refresh-secs` /
+/// `BUZZ_ACP_CHANNEL_DISCOVERY_REFRESH_SECS`. 0 disables.
+pub(crate) const DEFAULT_CHANNEL_DISCOVERY_REFRESH_SECS: u64 = 90;
+
 #[derive(Debug, Error)]
 pub enum ConfigError {
     #[error("failed to parse nostr keys: {0}")]
@@ -387,6 +399,16 @@ pub struct CliArgs {
     #[arg(long, env = "BUZZ_ACP_NO_TYPING")]
     pub no_typing: bool,
 
+    /// Seconds between periodic channel re-discovery sweeps that reconcile
+    /// missed channel joins and removals. 0 disables the sweep; live membership
+    /// notifications remain active either way.
+    #[arg(
+        long,
+        env = "BUZZ_ACP_CHANNEL_DISCOVERY_REFRESH_SECS",
+        default_value_t = DEFAULT_CHANNEL_DISCOVERY_REFRESH_SECS
+    )]
+    pub channel_discovery_refresh_secs: u64,
+
     /// Enable NIP-AE agent core memory injection.
     ///
     /// Memory injection is on by default. When enabled, the harness
@@ -547,6 +569,9 @@ pub struct Config {
     pub max_turns_per_session: u32,
     pub presence_enabled: bool,
     pub typing_enabled: bool,
+    /// Seconds between periodic channel re-discovery sweeps. 0 = disabled.
+    /// See [`DEFAULT_CHANNEL_DISCOVERY_REFRESH_SECS`].
+    pub channel_discovery_refresh_secs: u64,
     /// Whether NIP-AE agent core memory injection is enabled. When false,
     /// the harness skips the per-session core engram fetch and renders no
     /// `[Agent Memory — core]` section. On by default; disabled via the
@@ -1123,6 +1148,7 @@ impl Config {
             max_turns_per_session: args.max_turns_per_session,
             presence_enabled: !args.no_presence,
             typing_enabled: !args.no_typing,
+            channel_discovery_refresh_secs: args.channel_discovery_refresh_secs,
             memory_enabled: args.memory && !args.no_memory,
             model,
             effort_level: args.effort_level,
@@ -1499,6 +1525,7 @@ mod tests {
             max_turns_per_session: 0,
             presence_enabled: true,
             typing_enabled: true,
+            channel_discovery_refresh_secs: DEFAULT_CHANNEL_DISCOVERY_REFRESH_SECS,
             memory_enabled: true,
             model: None,
             effort_level: None,