DEVX-118: feat: enhance documentation-as-code with badges, version refs, Vale

- Fix badge system: clean .badges dir from orphan branch, add version
  verification, make badges job depend on release (avoids stale version
  badge race condition)
- Add check_doc_versions.py: lint tool that verifies docs version
  references match current __version__, with --fix for auto-update
- Integrate check_doc_versions into release process (auto-updates docs
  on every release commit)
- Add Vale prose linter integration: .vale.ini, custom styles for
  terminology and code block language, CI step, make target
- Fix stale version references in docs (0.27.0 → 0.33.4)
- Fix e.g. → for example in docs (Google.Latin Vale rule)
- Add CI steps for check_doc_versions and Vale to quality workflow
- Add make targets: devx-check-doc-versions, devx-vale

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

.vale.ini

@@ -0,0 +1,46 @@
+# Vale configuration for devx documentation
+# https://vale.sh/docs/
+
+StylesPath = .vale/styles
+
+# Packages are downloaded via `vale sync`
+Packages = write-good, Google, Readability
+
+# Minimum alert level to display (suggestion, warning, error)
+MinAlertLevel = warning
+
+# Project vocabulary — terms not flagged as spelling errors
+Vocab = devx
+
+[*.{md}]
+# Enable style guides
+BasedOnStyles = Vale, write-good, Google, Readability, devx
+
+# Google style — relax rules too strict for technical docs
+Google.Contractions = NO
+Google.WordList = NO
+Google.Acronyms = NO
+Google.We = NO
+Google.Will = NO
+Google.Colons = NO
+Google.Headings = NO
+Google.EmDash = NO
+Google.Units = NO
+
+# write-good — relax rules too strict for technical writing
+write-good.E-Prime = NO
+write-good.So = NO
+write-good.ThereIs = NO
+write-good.TooWordy = NO
+
+# Vale defaults — spelling catches too many technical terms
+Vale.Terms = NO
+Vale.Repetition = NO
+Vale.Spelling = NO
+
+# Readability — warnings only, technical docs are naturally complex
+Readability.FleschReadingEase = suggestion
+Readability.ColemanLiau = suggestion
+Readability.LIX = suggestion
+Readability.GunningFog = suggestion
+Readability.SMOG = suggestion