refactor!: retire wails.json, config.yml is the version source

- version.go (generated, never hand-edited) carries the compiled-in
  version; app.go drops the wails.json embed plus the gjson dependency
- make release bumps config.yml and regenerates version.go in one
  commit; the re-run-safe guards from the 1.99.1 cycle carry over
- release guard reads config.yml; CI CLI pin and cache key move to
  beta.22 to match the lockstep above
- release wrapper and config NOTE comments updated; deletion proof:
  wails3 build green plus a dev boot reaching the connected state
  with the file absent (the one cold-boot failure reproduced as a
  Vite 8 cold-start vs app retry race, cleared by rerunning warm)

Makefile

@@ -11,22 +11,26 @@ build:
 clean:
 	rm -rf build/bin/*
 
-# Create a version commit (wails.json bump, committed and pushed) plus an
+# Create a version commit (version bump, committed and pushed) plus an
 # annotated version tag carrying auto-generated release notes (git-cliff),
 # and push both. The tag push triggers .gitea/workflows/release.yml, which
-# verifies wails.json matches the tag, builds via `make build`, packages
+# verifies build/config.yml matches the tag, builds via `make build`, packages
 # AniTrack-<VERSION>.tar.gz from build/, and publishes a Gitea Release
 # named AniTrack-<VERSION> with the archive attached. Notes come entirely
 # from Conventional Commits — no hand-written message required.
 #
+# The single version source is build/config.yml info.version. `make release`
+# bumps it and regenerates version.go (the compiled-in copy) from it, so the
+# two can never drift; both ride the same bump commit.
+#
 # git-cliff's --latest needs the tag to exist to scope the notes, so we
 # create a throwaway lightweight tag, generate the notes, replace it with
 # an annotated tag, then push. --cleanup=verbatim keeps the markdown "###"
 # group headers (git's default cleanup would strip lines starting with "#").
 #
-# Tags are plain versions (1.6.7) to match wails.json productVersion and the
-# existing tag history. Pre-releases are created by tagging manually with a
-# suffix (e.g. 1.6.7-rc1 on top of the bumped commit) — the workflow marks
+# Tags are plain versions (1.6.7) to match build/config.yml info.version and
+# the existing tag history. Pre-releases are created by tagging manually with
+# a suffix (e.g. 1.6.7-rc1 on top of the bumped commit) — the workflow marks
 # those as prerelease. Use ./release as a shortcut.
 #
 # Requires git-cliff: https://git-cliff.org/install
@@ -35,17 +39,14 @@ release:
 	@test -n "$(VERSION)" || { echo "Usage: make release VERSION=1.6.7"; exit 1; }
 	@echo "$(VERSION)" | grep -Eq '^[0-9]+\.[0-9]+\.[0-9]+$$' || { echo "VERSION must be plain semver like 1.6.7 (no v prefix, no AniTrack- prefix, no suffix)"; exit 1; }
 	@command -v git-cliff >/dev/null 2>&1 || { echo "git-cliff not found — install: https://git-cliff.org/install"; exit 1; }
-	@command -v python3 >/dev/null 2>&1 || { echo "python3 not found — required to bump wails.json"; exit 1; }
+	@command -v python3 >/dev/null 2>&1 || { echo "python3 not found — required to bump versions"; exit 1; }
 	@git diff --quiet && git diff --cached --quiet || { echo "Working tree dirty — commit or stash first"; exit 1; }
 	@if git rev-parse "$(VERSION)" >/dev/null 2>&1; then echo "Tag $(VERSION) already exists locally — delete it first: git tag -d $(VERSION)"; exit 1; fi
-	@echo "Bumping wails.json to $(VERSION)..."
-	@python3 -c "import json; p='wails.json'; d=json.load(open(p)); d['info']['productVersion']='$(VERSION)'; json.dump(d, open(p,'w'), indent=2); open(p,'a').write('\n')"
-	# TEMP until wails.json (v2 leftover) is retired: bump build/config.yml too.
-	# The regex targets only the indented info.version line, never the
-	# top-level schema `version: '3'`.
 	@echo "Bumping build/config.yml to $(VERSION)..."
 	@python3 -c "import re; p='build/config.yml'; s=open(p).read(); m=re.search(r'^  version: \"([^\"]*)\"', s, flags=re.M); assert m, 'info.version not found'; print('build/config.yml', m.group(1), '-> $(VERSION)' if m.group(1) != '$(VERSION)' else '(already at version)'); open(p,'w').write(re.sub(r'^  version: \"[^\"]*\"', '  version: \"$(VERSION)\"', s, count=1, flags=re.M))"
-	@git add wails.json build/config.yml
+	@echo "Regenerating version.go from build/config.yml..."
+	@python3 -c "import re; v=re.search(r'^  version: \"([^\"]*)\"', open('build/config.yml').read(), flags=re.M).group(1); open('version.go','w').write('package main\n\n// Code generated by \`make release\` from build/config.yml info.version.\n// DO NOT EDIT.\nconst appVersionString = \"%s\"\n' % v)"
+	@git add build/config.yml version.go
 	@git diff --cached --quiet && echo "versions already at $(VERSION), skipping bump commit" || git commit -m "chore(release): bump version to $(VERSION)"
 	@echo "Generating release notes for $(VERSION)..."
 	@git tag "$(VERSION)" HEAD && \