feat: Go resolution statistics in resolution-report command

[shivasurya]

Summary

• Wires the full Go call graph pipeline into pathfinder resolution-report (same as scan.go): BuildGoModuleRegistry → InitGoStdlibLoader → InitGoThirdPartyLoader → BuildGoCallGraph → MergeCallGraphs, guarded by go.mod existence check
• Adds Go-specific fields to resolutionStatistics: GoTotalCalls, GoResolvedCalls, GoUnresolvedCalls, GoUserCodeResolved, GoStdlibResolved, GoThirdPartyResolved, GoStdlibByModule, GoThirdPartyByModule
• Classifies Go call sites using site.IsStdlib (authoritative for single-segment stdlib like fmt/os) and site.TypeSource ("thirdparty_local" / "thirdparty_cdn")
• New helpers: extractGoModuleName, printTopModules, printGoResolutionStatistics
• 9 new tests — all three new functions at 100% coverage, aggregateResolutionStatistics bumped to 100%

Why

Without this PR there is no way to measure Go resolution rates. The resolution report is the observability layer for the entire Go third-party resolution feature — it answers whether the 97%+ resolution target from the tech spec is being hit on real projects.

Dependencies

Stacked on PR-04 (shiva/pr-04-golang-thirdparty).

Expected output

Go Resolution Statistics:
  Total Go calls:       45
  Resolved:             42 (93.3%)
  Unresolved:           3 (6.7%)

  Resolution Breakdown:
    User code:          12 (28.6%)
    Stdlib (CDN):       20 (47.6%)
    Third-party:        10 (23.8%)

  Top Go Stdlib Modules:
     1. net/http                                    8 calls
     2. fmt                                         5 calls

  Top Go Third-Party Modules:
     1. gorm.io/gorm                                4 calls
     2. github.com/gin-gonic/gin                    3 calls

Test plan

• go build ./cmd/... — zero errors
• go test ./cmd/... -count=1 — all pass
• golangci-lint run ./cmd/... — zero issues
• CI green

🤖 Generated with Claude Code

[safedep]

SafeDep Report Summary

No dependency changes detected. Nothing to scan.

View complete scan results →

_{This report is generated by SafeDep Github App}

[github-actions]

Code Pathfinder Security Scan

No security issues detected.

Metric	Value
Files Scanned	2
Rules	205

---

_{Powered by Code Pathfinder}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.38%. Comparing base (61d181d) to head (5f5a0af).

Additional details and impacted files

@@                        Coverage Diff                        @@
##           shiva/pr-04-golang-thirdparty     #645      +/-   ##
=================================================================
+ Coverage                          84.24%   84.38%   +0.14%     
=================================================================
  Files                                162      162              
  Lines                              23358    23449      +91     
=================================================================
+ Hits                               19677    19787     +110     
+ Misses                              2941     2917      -24     
- Partials                             740      745       +5     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.