refactor: rename McpPort to MCPPort for Go naming conventions

[mvanhorn]

Summary

• Renames Go struct field McpPort to MCPPort and method GetMcpPort to GetMCPPort across 15 files to follow Go's all-caps acronym convention
• JSON tag mcpPort is unchanged, so no wire-format or API breaking change

Test plan

• All affected packages compile (go build ./cmd/thv-operator/... ./pkg/export/... ./pkg/vmcp/...)
• CI passes

Closes #4582

[ChrisJBurns]

@mvanhorn You have an out of date branch/merge conflicts

[mvanhorn]

Rebased onto current main in 9642bfc. Also caught 3 additional files that upstream changed since the original PR - applied the McpPort -> MCPPort rename to those as well (integration and scaling tests).

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 68.84%. Comparing base (f5d8015) to head (f258512).
⚠️ Report is 20 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4589      +/-   ##
==========================================
- Coverage   68.85%   68.84%   -0.01%     
==========================================
  Files         505      509       +4     
  Lines       52425    52698     +273     
==========================================
+ Hits        36096    36280     +184     
- Misses      13536    13614      +78     
- Partials     2793     2804      +11     

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[ChrisJBurns]

@mvanhorn there's some CRD steps you need to do. some task operator-manifests task crdref-gen etc

[mvanhorn]

Ran task operator-manifests and task crdref-gen in f258512 - the generated CRD files and docs now reflect the MCPPort rename.

[ChrisJBurns]

@mvanhorn ahhh almost there, we got some lint checks now