fix(sync): inspect hidden server listeners via procfs

Cargo.lock

@@ -1642,7 +1642,7 @@ checksum = "09edd9e8b54e49e587e4f6295a7d29c3ea94d469cb40ab8ca70b288248a81db2"
 
 [[package]]
 name = "lesavka_client"
-version = "0.14.35"
+version = "0.14.36"
 dependencies = [
  "anyhow",
  "async-stream",
@@ -1676,7 +1676,7 @@ dependencies = [
 
 [[package]]
 name = "lesavka_common"
-version = "0.14.35"
+version = "0.14.36"
 dependencies = [
  "anyhow",
  "base64",
@@ -1688,7 +1688,7 @@ dependencies = [
 
 [[package]]
 name = "lesavka_server"
-version = "0.14.35"
+version = "0.14.36"
 dependencies = [
  "anyhow",
  "base64",

client/Cargo.toml

@@ -4,7 +4,7 @@ path                    = "src/main.rs"
 
 [package]
 name                    = "lesavka_client"
-version                 = "0.14.35"
+version                 = "0.14.36"
 edition                 = "2024"
 
 [dependencies]

common/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name                    = "lesavka_common"
-version                 = "0.14.35"
+version                 = "0.14.36"
 edition                 = "2024"
 build                   = "build.rs"
 

scripts/install/server.sh

@@ -128,7 +128,59 @@ server_bind_port() {
 list_server_listener_pids() {
   local port
   port=$(server_bind_port) || return 1
-  sudo lsof -tiTCP:"$port" -sTCP:LISTEN 2>/dev/null | sort -u
+  {
+    sudo lsof -tiTCP:"$port" -sTCP:LISTEN 2>/dev/null || true
+    list_server_listener_pids_proc "$port"
+  } | sed '/^$/d' | sort -u
+}
+
+list_server_listener_inodes_proc() {
+  local port=$1 hex_port
+  hex_port=$(printf '%04X' "$port")
+  sudo awk -v target="$hex_port" '
+    FNR == 1 { next }
+    $4 == "0A" {
+      split($2, local, ":")
+      if (toupper(local[2]) == target) print $10
+    }
+  ' /proc/net/tcp /proc/net/tcp6 2>/dev/null | sed '/^$/d' | sort -u
+}
+
+list_server_listener_pids_proc() {
+  local port=$1
+  local -a inodes=()
+  mapfile -t inodes < <(list_server_listener_inodes_proc "$port")
+  if (( ${#inodes[@]} == 0 )); then
+    return 0
+  fi
+
+  sudo bash -s -- "${inodes[@]}" <<'EOF'
+set -euo pipefail
+inodes=("$@")
+shopt -s nullglob
+for fd in /proc/[0-9]*/fd/*; do
+  target=$(readlink "$fd" 2>/dev/null || true)
+  for inode in "${inodes[@]}"; do
+    if [[ "$target" == "socket:[$inode]" ]]; then
+      pid=${fd#/proc/}
+      pid=${pid%%/*}
+      printf '%s\n' "$pid"
+      break
+    fi
+  done
+done | sort -u
+EOF
+}
+
+server_listener_presence_detail() {
+  local port=$1
+  local -a inodes=()
+  mapfile -t inodes < <(list_server_listener_inodes_proc "$port")
+  if (( ${#inodes[@]} == 0 )); then
+    printf 'no /proc listener entries for :%s' "$port"
+    return 0
+  fi
+  printf 'listener inodes on :%s => %s' "$port" "${inodes[*]}"
 }
 
 clear_stale_server_listener() {
@@ -155,6 +207,10 @@ clear_stale_server_listener() {
     return 1
   fi
   if [[ "$found" == "0" ]]; then
+    if list_server_listener_inodes_proc "$port" | grep -q .; then
+      echo "❌ TCP :$port is listening but no owning PID could be identified; $(server_listener_presence_detail "$port")." >&2
+      return 1
+    fi
     return 0
   fi
 
@@ -186,6 +242,11 @@ clear_stale_server_listener() {
     sleep 0.1
   done
 
+  if list_server_listener_inodes_proc "$port" | grep -q .; then
+    echo "❌ TCP :$port still appears to be listening after cleanup; $(server_listener_presence_detail "$port")." >&2
+    return 1
+  fi
+
   echo "❌ lesavka-server listener on :$port survived cleanup; refusing to start a duplicate server." >&2
   return 1
 }

server/Cargo.toml

@@ -10,7 +10,7 @@ bench                   = false
 
 [package]
 name                    = "lesavka_server"
-version                 = "0.14.35"
+version                 = "0.14.36"
 edition                 = "2024"
 autobins                = false
 

testing/tests/server_install_script_contract.rs

@@ -114,10 +114,22 @@ fn server_install_pins_hdmi_camera_and_display_defaults() {
         SERVER_INSTALL.contains("lsof -tiTCP:"),
         "install script should inspect the bind port before starting a fresh server"
     );
+    assert!(
+        SERVER_INSTALL.contains("/proc/net/tcp"),
+        "install script should fall back to procfs listener detection when lsof misses the owner"
+    );
+    assert!(
+        SERVER_INSTALL.contains("socket:["),
+        "install script should map listening socket inodes back to owning PIDs"
+    );
     assert!(
         SERVER_INSTALL.contains("unexpected process"),
         "install script should fail loud instead of killing an unrelated process on the server port"
     );
+    assert!(
+        SERVER_INSTALL.contains("no owning PID could be identified"),
+        "install script should fail loud when a port is listening but procfs cannot identify the owner"
+    );
     assert!(
         SERVER_INSTALL.contains("validate_server_ready"),
         "install script should verify that lesavka-server reaches a running state"