Fix mkdocs strict-build warnings before v1.0 release (FritzAndFriends#564)

* fix: Documentation build issues — add missing nav entries and fix broken links

- Add Migration/InlineCSharp.md to mkdocs.yml nav (was missing from documentation index)
- Fix BWFC022.md reference to ClientScriptMigrationGuide (simplify to direct link)
- Remove TODO image reference in Analyzers.md (bwfc025-warning-squiggle.png not needed for v1.0.0)
- All mkdocs build warnings now cleared in strict mode

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* docs: fix ClientScriptMigrationGuide anchor links for strict build

- Correct BWFC022 cross-file anchor to ClientScriptMigrationGuide heading
- Correct internal anchor link in ClientScriptMigrationGuide
- Keep mkdocs --strict build green in CI

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

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Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: csharpfritz