feat: port session 07 — Protocol Parser, Auth extras (TPM/certidp/certstore), Internal utilities & data structures

Session 07 scope (5 features, 17 tests, ~1165 Go LOC):
- Protocol/ParserTypes.cs: ParserState enum (79 states), PublishArgument, ParseContext
- Protocol/IProtocolHandler.cs: handler interface decoupling parser from client
- Protocol/ProtocolParser.cs: Parse(), ProtoSnippet(), OverMaxControlLineLimit(),
  ProcessPub/HeaderPub/RoutedMsgArgs/RoutedHeaderMsgArgs, ClonePubArg(), GetHeader()
- tests/Protocol/ProtocolParserTests.cs: 17 tests via TestProtocolHandler stub

Auth extras from session 06 (committed separately):
- Auth/TpmKeyProvider.cs, Auth/CertificateIdentityProvider/, Auth/CertificateStore/

Internal utilities & data structures (session 06 overflow):
- Internal/AccessTimeService.cs, ElasticPointer.cs, SystemMemory.cs, ProcessStatsProvider.cs
- Internal/DataStructures/GenericSublist.cs, HashWheel.cs
- Internal/DataStructures/SubjectTree.cs, SubjectTreeNode.cs, SubjectTreeParts.cs

All 461 tests pass (460 unit + 1 integration). DB updated for features 2588-2592 and tests 2598-2614.

docs/plans/phases/phase6sessions/session-02.md

@@ -0,0 +1,42 @@
+# Session 02: Utilities & Queues
+
+## Summary
+
+General utility functions, IP-based queue, send queue, task scheduler, and subject transform engine. These are infrastructure pieces used across the server.
+
+## Scope
+
+| Go File | Features | Feature IDs | Go LOC |
+|---------|----------|-------------|--------|
+| server/util.go | 21 | 3485–3505 | 244 |
+| server/ipqueue.go | 14 | 1354–1367 | 175 |
+| server/sendq.go | 3 | 2971–2973 | 76 |
+| server/scheduler.go | 14 | 2952–2965 | 260 |
+| server/subject_transform.go | 16 | 3388–3403 | 570 |
+| **Total** | **68** | | **1,325** |
+
+## .NET Classes
+
+- `ServerUtilities` — string/byte helpers, random, hashing
+- `IpQueue<T>` — lock-free concurrent queue with IP grouping
+- `SendQueue` — outbound message queue
+- `Scheduler` — time-based task scheduler
+- `SubjectTransform` — NATS subject rewriting/mapping engine
+
+## Test Files
+
+| Test File | Tests | Test IDs |
+|-----------|-------|----------|
+| server/util_test.go | 13 | 3061–3073 |
+| server/ipqueue_test.go | 28 | 688–715 |
+| server/subject_transform_test.go | 4 | 2958–2961 |
+| server/split_test.go | 12 | 2929–2940 |
+| **Total** | **57** | |
+
+## Dependencies
+
+- Session 01 (Foundation Types)
+
+## .NET Target Location
+
+- `dotnet/src/ZB.MOM.NatsNet.Server/Internal/`