[codex] Harden Board-Man upgrade CTA

[uniplanck]

Summary

• Added a shared Board-Man Pro upgrade URL opener.
• Replaced direct Pro upgrade CTA URL opening with the safe shared route.
• Kept UI, entitlement behavior, purchase flow, backend, Keychain, and release settings unchanged.

Files changed

• Board-Man.xcodeproj/project.pbxproj
• Clipy/Sources/Preferences/CPYPreferencesWindowController.swift
• Clipy/Sources/Preferences/Panels/CPYBetaPreferenceViewController.swift
• Clipy/Sources/Services/BoardManUpgradeRoute.swift

URL helper added/updated

• Added BoardManUpgradeRoute.openProPage() with the canonical URL https://uniplanck.com/board-man.
• The helper avoids force-unwrapping, logs/asserts lightly on invalid URL construction, and opens only after safe URL creation.

Call sites changed

• License free state UI openBuyPro() now calls BoardManUpgradeRoute.openProPage().
• Pro locked Appearance control openBoardManProUpgrade() now calls BoardManUpgradeRoute.openProPage().

Validation results

• git status --short: expected branch changes only before commit, with unrelated untracked _copy/ left unstaged.
• git diff --stat: 4 files changed, 27 insertions, 2 deletions.
• git diff --check: passed.
• rtk xcodebuild -project Board-Man.xcodeproj -scheme Board-Man -configuration Debug -derivedDataPath "${TMPDIR:-/tmp}/BoardManCodexValidation" -destination 'generic/platform=macOS' -skipPackagePluginValidation -skipMacroValidation CODE_SIGNING_ALLOWED=NO build: passed with existing SwiftLint warnings.\n\n## Explicitly out of scope\n- UI redesign\n- purchase flow\n- real license activation\n- backend activation\n- Keychain device binding\n- Sparkle release/appcast