Polish sweep: SHA-pin comments, module count, and test count verification (#45)

## Summary

Completes W2-8 polish sweep checklist items:
1. **README module count**: Updated from 40 to 41 modules to match
actual `src/stats/*.jl` file count
2. **SHA-pin version comment normalization**: Fixed comment mismatch in
`casket-pages.yml` and `secret-scanner.yml` — updated from "# v4" to "#
v7.0.0" for SHA 9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0
(actions/checkout v7.0.0)
3. **Verification**: `git-cliff` (v2.13.1) and
`softprops/action-gh-release` (v3.0.1) SHA-pinning already correct in
`release.yml`

## Test Count Correction

**IMPORTANT**: The commit message claims 4975 tests pass, but
verification shows the actual count is **5595 tests**:
- Full Test Suite: 424
- E2E Pipeline Tests: 155  
- Property-Based Tests: 3800
- Reference Validation: 62
- Degenerate Input Guards: 943
- Neural-Boundary Guardrail: 80
- Executor Router Coverage: 131
- **Total: 5595**

This is higher than the documented baseline (4404) because Wave 1 tasks
(W1-2, W1-6, W1-7) added new test categories (Degenerate, Guardrail,
Router coverage). The commit message test count should be updated in a
follow-up or noted as known issue.

## Items Already Resolved by Prior PRs

The following W2-8 checklist items were already handled by previous PRs
and were not revisited:
- W1-2 (#40): Undefined-stat sentinels (harmonic_mean, cv,
geometric_mean return nothing + reason)
- W1-4 (#34): .tool-versions with julia 1.10.x; Project.toml [compat]
entries
- W1-8/#33: Template banners removed from CODE_OF_CONDUCT.md and
docs/AI_INSTALLATION_GUIDE.adoc
- W1-6/#38: build.zig dead refs (include/statistikles.h,
bench/bench.zig) removed
- #33: CODEOWNERS deduplicated

## Verification

Full Julia test suite verified green (5595 tests) via `flock
/tmp/statistikles-julia.lock -c 'julia --project=. -e "using Pkg;
Pkg.test()"'`

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Haiku 4.5 <noreply@anthropic.com>

Author: hyperpolymath

.github/workflows/casket-pages.yml

@@ -20,9 +20,9 @@ jobs:
     timeout-minutes: 60
     steps:
       - name: Checkout
-        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v4
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
       - name: Checkout casket-ssg
-        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v4
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
         with:
           repository: hyperpolymath/casket-ssg
           path: .casket-ssg

.github/workflows/secret-scanner.yml

@@ -20,7 +20,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 15
     steps:
-      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v4
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
         with:
           fetch-depth: 0 # Full history for scanning
       - name: TruffleHog Secret Scan
@@ -34,7 +34,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 15
     steps:
-      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v4
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
       - name: Check for hardcoded secrets in Rust
         run: |
           if ! find . -name Cargo.toml -not -path './target/*' -print -quit | grep -q .; then

README.adoc

@@ -58,9 +58,9 @@ hard architectural invariant.
 
 == Features
 
-=== Statistical Functions (40 Modules)
+=== Statistical Functions (41 Modules)
 
-The table below is a curated highlight — the full set of 40 modules lives in
+The table below is a curated highlight — the full set of 41 modules lives in
 `src/stats/` (including survival, spatial, robust, time-series, meta-analysis,
 NLP, and non-classical statistics).