S264: stale socket cleanup — daemon shutdown + display Drop + SIGTERM + clippy sweep

primalSpring stale socket audit response: all 6 UDS bind sites already
clean (unlink before bind). Fixed two production gaps:

- CLI daemon shutdown was a no-op stub — now removes socket file
- CLI daemon only handled ctrl_c — now handles SIGTERM via tokio signal
- DisplayServer had no Drop impl — now removes display.sock on drop
- Fixed 20+ Rust 1.92 clippy issues across upstream code (new_without_default,
  unnecessary_literal_bound, type_complexity, items_after_statements,
  collection_is_never_read, single_match_else, io_other_error, etc.)
- 85 JSON-RPC methods, 9,028 lib tests, 0 clippy warnings, deny clean

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: BiomeOS Developer

.env.example

@@ -1,5 +1,5 @@
 # ToadStool Environment Configuration
-# Updated: S263 (May 17, 2026)
+# Updated: S264 (May 18, 2026)
 #
 # All values have sensible defaults. Only override what you need.
 # Copy this file to .env and customize for your environment.

CHANGELOG.md

@@ -5,7 +5,20 @@ All notable changes to ToadStool will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [Unreleased] - May 17, 2026 (Sessions 43-263)
+## [Unreleased] - May 18, 2026 (Sessions 43-264)
+
+### Session S264 (May 18, 2026) — Stale Socket Cleanup: primalSpring Audit Response
+
+primalSpring stale socket cleanup audit response: server-side socket hygiene hardened.
+
+- FIXED: CLI daemon shutdown now removes socket file (was no-op stub)
+- FIXED: CLI daemon now handles SIGTERM in addition to SIGINT (was ctrl_c only)
+- ADDED: `DisplayServer` Drop impl — removes display socket on drop
+- AUDITED: All 6 UDS bind sites already do `unlink()` before `bind()` (no changes needed)
+- AUDITED: UniBin server already cleans up both sockets + legacy symlink on SIGINT/SIGTERM
+- AUDITED: `IpcServer::Drop` already removes Unix socket files
+- FIXED: 20+ pre-existing Rust 1.92 clippy issues across upstream code (`if_not_else`, `ignored_unit_patterns`, `collapsible_if`, `map_unwrap_or`, `default_trait_access`, `new_without_default`, `unnecessary_literal_bound`, `type_complexity`, `needless_late_init`, `too_many_arguments`, `items_after_statements`, `used_underscore_binding`, `collection_is_never_read`, `single_match_else`, `io_other_error`, `match_wildcard_for_single_variants`, `unfulfilled_lint_expectations`)
+- METRICS: 85 JSON-RPC methods (direct), 9,028 lib tests, 0 clippy warnings, deny clean
 
 ### Session S263 (May 17, 2026) — Stadial Gate: primalSpring Audit Response
 

DEBT.md

@@ -1,6 +1,6 @@
 # Active Technical Debt Register
 
-**Date**: May 2026 — S263
+**Date**: May 2026 — S264
 **Philosophy**: Math is universal, precision is silicon. Workarounds are
 short-term solutions that increase debt. We aim to solve deep debt over
 iterations, evolving toward vendor-agnostic, capability-based solutions—

DOCUMENTATION.md

@@ -1,6 +1,6 @@
 # ToadStool Documentation Hub
 
-**Last Updated**: May 2026 — S263
+**Last Updated**: May 2026 — S264
 
 ---
 

README.md

@@ -1,6 +1,6 @@
 # ToadStool
 
-**Sovereign Compute Hardware** | Pure Rust | ecoBin | May 2026 | S263 | v0.2.0
+**Sovereign Compute Hardware** | Pure Rust | ecoBin | May 2026 | S264 | v0.2.0
 
 ---
 
@@ -42,7 +42,7 @@ Nest    = Tower  + Storage            <- storage
 | `cargo fmt --all -- --check` | 0 diffs |
 | `cargo clippy --workspace --all-targets -- -D warnings` | 0 warnings |
 | `cargo doc --workspace --no-deps` (RUSTDOCFLAGS="-D warnings") | 0 warnings |
-| `cargo test --workspace` | **22,900+ tests, 0 failures** (8,945+ lib-only), **~222** ignored (hardware-gated); full workspace ~7m |
+| `cargo test --workspace` | **23,000+ tests, 0 failures** (9,028+ lib-only), **~222** ignored (hardware-gated); full workspace ~7m |
 | Doctests | All passing (common, core, server, cli, testing, display) |
 | Standalone clone test | Pull to any machine, `cargo test` works (GPU-optional, CPU fallback, device-lost resilient) |
 | `unsafe` blocks | **46 actual** (all in hw-safe/GPU/VFIO/display/plugin containment crates); all SAFETY-documented (S204, reconciled S221); workspace `unsafe_code = "deny"`, **41 crates `forbid`** + 5 hw crates with narrow `#[allow(unsafe_code, reason)]`; **all lint attrs have `reason =`** (S211+S213) |

crates/cli/src/daemon/server.rs

@@ -8,9 +8,9 @@
 //! - Workload lifecycle management
 
 use crate::Result;
+use std::path::PathBuf;
 use std::sync::Arc;
 use toadstool_common::platform_paths::{PathEnv, PlatformPaths};
-use tokio::signal;
 use tracing::{info, warn};
 
 use super::config::DaemonConfig;
@@ -30,6 +30,9 @@ pub struct DaemonServer {
 
     /// Workload manager
     workload_manager: Arc<WorkloadManager>,
+
+    /// Socket path used for the JSON-RPC listener (for cleanup on shutdown).
+    socket_path: PathBuf,
 }
 
 impl DaemonServer {
@@ -75,28 +78,29 @@ impl DaemonServer {
             }
         }
 
+        let socket_path = config.socket_path.clone().unwrap_or_else(|| {
+            let env = PathEnv::from_env();
+            PlatformPaths::new(&env).toadstool_socket()
+        });
+
         info!("✅ ToadStool daemon server initialized");
 
         Ok(Self {
             config,
             workload_manager: Arc::new(workload_manager),
+            socket_path,
         })
     }
 
     /// Run the daemon server until shutdown signal
     pub async fn run(self) -> Result<()> {
-        let socket_path = self.config.socket_path.clone().unwrap_or_else(|| {
-            let env = PathEnv::from_env();
-            PlatformPaths::new(&env).toadstool_socket()
-        });
-
         info!("🚀 ToadStool daemon running");
-        info!("🍄 JSON-RPC socket: {}", socket_path.display());
+        info!("🍄 JSON-RPC socket: {}", self.socket_path.display());
         info!("📊 Methods: daemon.health, daemon.metrics, daemon.submit_workload, etc.");
 
         // Start JSON-RPC Unix socket server
         {
-            let socket = socket_path.clone();
+            let socket = self.socket_path.clone();
             let manager = Arc::clone(&self.workload_manager);
 
             tokio::spawn(async move {
@@ -120,37 +124,57 @@ impl DaemonServer {
 
         info!("✨ JSON-RPC over UDS per wateringHole standard");
 
-        // Wait for shutdown signal
-        signal::ctrl_c().await?;
+        // Wait for SIGINT or SIGTERM
+        wait_for_shutdown().await;
 
         info!("🛑 Shutdown signal received");
 
-        // Graceful shutdown
+        // Graceful shutdown — clean up socket files
         self.shutdown().await?;
 
         info!("👋 ToadStool daemon stopped");
         Ok(())
     }
 
-    /// Graceful shutdown
-    #[expect(
-        clippy::unused_async,
-        reason = "async signature required by trait/interface"
-    )] // Shutdown hook; async for future extension
+    /// Graceful shutdown — remove socket files to prevent stale socket accumulation.
     async fn shutdown(&self) -> Result<()> {
         info!("🧹 Performing graceful shutdown...");
 
-        // Shutdown sequence:
-        // 1. Stop accepting new workloads
-        // 2. Stop JSON-RPC servers (Unix + TCP)
-        // 3. Gracefully terminate running workloads
-        // 4. Unregister from coordination service (if registered)
+        if self.socket_path.exists() {
+            match tokio::fs::remove_file(&self.socket_path).await {
+                Ok(()) => info!("Removed socket: {}", self.socket_path.display()),
+                Err(e) => warn!("Failed to remove socket {}: {e}", self.socket_path.display()),
+            }
+        }
 
         info!("✅ Shutdown complete");
         Ok(())
     }
 }
 
+/// Wait for SIGINT (Ctrl+C) or SIGTERM.
+async fn wait_for_shutdown() {
+    #[cfg(unix)]
+    {
+        use tokio::signal::unix::{SignalKind, signal};
+
+        let mut sigint =
+            signal(SignalKind::interrupt()).expect("failed to register SIGINT handler");
+        let mut sigterm =
+            signal(SignalKind::terminate()).expect("failed to register SIGTERM handler");
+
+        tokio::select! {
+            _ = sigint.recv() => info!("Received SIGINT"),
+            _ = sigterm.recv() => info!("Received SIGTERM"),
+        }
+    }
+
+    #[cfg(not(unix))]
+    {
+        let _ = tokio::signal::ctrl_c().await;
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

crates/core/cylinder/src/hardware.rs

@@ -198,7 +198,7 @@ pub trait BootPipeline: Send + Sync + std::fmt::Debug {
     type InitResult: std::fmt::Debug + Clone;
 
     /// Device family name (e.g. "Kepler", "Volta", "Vega 20").
-    fn device_family(&self) -> &str;
+    fn device_family(&self) -> &'static str;
 
     /// Phase 1: Probe the device — read identity registers, detect warm/cold.
     fn probe(

crates/core/cylinder/src/vfio/amd_metal.rs

@@ -376,6 +376,12 @@ pub struct VegaInit {
     bdf: Option<String>,
 }
 
+impl Default for VegaInit {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl VegaInit {
     /// Create a Vega pipeline with no BDF.
     pub fn new() -> Self {
@@ -394,7 +400,7 @@ impl BootPipeline for VegaInit {
     type ProbeResult = VegaProbeResult;
     type InitResult = VegaInitResult;
 
-    fn device_family(&self) -> &str {
+    fn device_family(&self) -> &'static str {
         "Vega 20"
     }
 

crates/core/cylinder/src/vfio/boot_state.rs

@@ -177,6 +177,9 @@ impl SovereignBootState {
     }
 }
 
+/// Strategy-provided closure that reads falcon registers and classifies state.
+pub type FalconDetector<'a> = &'a dyn Fn(&MappedBar, bool) -> FalconWarmState;
+
 /// Probe the GPU's boot state from BAR0 registers.
 ///
 /// This is the authoritative warm/cold classifier. It reads PMC_ENABLE,
@@ -188,7 +191,7 @@ impl SovereignBootState {
 /// probing (the state will default to `FalconWarmState::Cold`).
 pub fn probe_boot_state(
     bar0: &MappedBar,
-    detect_falcon: Option<&dyn Fn(&MappedBar, bool) -> FalconWarmState>,
+    detect_falcon: Option<FalconDetector<'_>>,
 ) -> SovereignBootState {
     let pmc_enable = bar0.read_u32(PMC_ENABLE).unwrap_or(0);
     let pmc_popcount = pmc_enable.count_ones();

crates/core/cylinder/src/vfio/clutch.rs

@@ -87,7 +87,6 @@ impl Clutch {
     /// # Errors
     ///
     /// Returns error if BAR0 region info ioctl fails or mmap fails.
-    #[expect(clippy::cast_possible_truncation, reason = "struct argsz always fits u32")]
     pub fn engage(
         bdf: &str,
         device_fd: BorrowedFd<'_>,