BUG FIXES:

  FastConcurrentQueue: Delete entire file (132 lines). Replaced with
  System.Collections.Concurrent.ConcurrentQueue<ProfilerResult> in
  ProfilerResultQueue. The custom FastConcurrentQueue/QueuePair/
  NullableArrayList implementation had unsynchronized Expand() in
  NullableArrayList causing two threads to share a single non-thread-safe
  Queue<T> instance, leading to Array.Copy failures and crashes under
  heavy concurrent profiling load.

  StringIndexer: Add lock around List<string> _mapping access.
  IndexOf() and StringAt() can be called concurrently from multiple
  threads via CustomProfiling.Profile() at runtime, corrupting the
  internal list state.

  ProfilerResultQueue consumer loop:
  - Remove racy _profilers.Count == 0 early-exit (non-atomic check
    allowed results to be silently dropped or accumulate unbounded)
  - Wrap consumer body in try/catch with retry (1s backoff, logs
    warning) to prevent silent consumer death causing unbounded
    memory growth
  - Only sleep when queue is empty (batch-drain, no forced 100ms
    batching penalty)
  - Drop Alternate() call (ConcurrentQueue handles concurrent
    read/write natively)

FEATURES:

  !profile diagnose command:
  - Runs 7 profilers simultaneously: GameLoopProfiler, GridProfiler,
    BlockTypeProfiler, PlayerProfiler, FactionProfiler, PhysicsProfiler,
    SessionComponentsProfiler
  - Tiered output: frame breakdown with percentages, top grids/block
    types/players/factions, physics clusters with per-grid drill-down,
    top session components
  - Discord-native formatting: bold headers, '>' block quotes,
    '—' separators, compact single-line frame breakdown; no code blocks
  - In-game chat format: compact line-by-line with abbreviated labels
  - Physics cluster drill-down queries HkWorld entities on game thread
    to identify top grids within each cluster
  - Player/faction grid counts computed on game thread for Discord output

BUILD:

  csproj: Add packaging targets (matching Advanced PB Limiter pattern)
  - Copy manifest.xml to output directory (PreserveNewest)
  - Zip output (DLL, PDB, manifest.xml) to Build/Profiler.zip
  - Uses PowerShell Compress-Archive for standard zip format (compatible
    with Torch PluginManager)
  - Remove unused packages.config reference

MISC:

  ProfilerCommands: Use C#8 'using var' declarations in existing commands