[codex] Implement runtime entitlement gates

[uniplanck]

Summary

• Connect runtime execution paths to the central EntitlementGate from PR [codex] Implement Board-Man entitlement core MVP #73.
• Fix Clipboard History to use retention/trim behavior instead of creation blocking.
• Keep pin/snippet/folder behavior as creation blocking at Free limits.
• No License UI, Appearance UI, activation/backend, Keychain/device binding, or Sparkle/release work added.

Files changed

• Clipy/Sources/Services/ClipService.swift
• Clipy/Sources/Services/Entitlement.swift
• Clipy/Sources/Managers/MenuManager.swift
• Clipy/Sources/Snippets/CPYSnippetsEditorWindowController.swift
• ClipyTests/EntitlementGateTests.swift

Runtime gates added

• Clipboard History: ClipService.save(with:) accepts new history items, then trims oldest entries to EntitlementGate.historyRetentionLimit().
• Pinned Items: PinnedSnippetStore.add(_:) uses EntitlementGate.canPinItem(currentPinnedCount:) before adding a new pin.
• Snippets: both snippet creation paths use EntitlementGate.canCreateSnippet(currentSnippetCount:).
• Snippet Folders: both folder/group creation paths use EntitlementGate.canCreateSnippetFolder(currentFolderCount:).

Free-limit behavior

• History: Free accepts a new item, then retains newest 100 items by trimming oldest entries during normal save flow.
• Pinned items: Free blocks new pins when current pinned count is at or above 3.
• Snippets: Free blocks new snippet creation when current snippet count is at or above 5.
• Snippet folders: Free blocks new folder/group creation when current folder count is at or above the configured folder limit.

Non-destructive behavior

• History over-limit data is only trimmed as part of normal history save/retention flow after accepting a new item.
• Existing over-limit pinned items, snippets, and folders are not deleted.
• Existing pinned items remain intact; additional pinning is blocked when over limit.
• Existing snippets/folders remain readable/editable through existing paths; only new creation is blocked.
• No destructive migration or bulk deletion was added.

Validation results

• rtk git status --short: only pre-existing untracked _copy/ remains after commit.
• rtk git diff --stat main...HEAD: 5 files changed, 90 insertions, 14 deletions.
• rtk git diff --check: passed.
• rtk git diff --cached --check: passed before commit.
• 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.

Tests / pure check

• Updated EntitlementGateTests for history retention, snippet folder limits, over-limit non-mutating behavior, and Pro runtime action allowance.
• Xcode test runner is still treated as out of scope because of the known IDELaunchServicesLauncher issue from PR [codex] Implement Board-Man entitlement core MVP #73.
• Pure Swift runtime entitlement check passed: ENTITLEMENT_RUNTIME_GATE_CHECK=OK.

Out of scope

• License UI
• Appearance UI
• backend activation
• Keychain device binding
• Sparkle release/appcast
• existing data migration/deletion