Add repo picker, update checker, and distribution tooling1.0.00.7.00.6.0

Closes #11-#15 (milestones 0.6.0, 0.7.0, 1.0.0).

- Repo picker: on-demand broader OAuth scope (security_events repo),
  requested only when the "Browse your repos" action is used, never by
  default. Lists /user/repos via the existing pagination helper. Granted
  scope persisted with backward-compatible decoding for existing state
  files. Fixed a bug where a failed re-auth force-signed-out a user who
  already had a valid narrower-scope token.
- Update checker: polls this repo's GitHub Releases API, surfaces a
  banner linking to new releases. Skipped on the Mac App Store build via
  a runtime receipt check rather than a separate build configuration.
- Fixed MARKETING_VERSION, stuck at Xcode's default "1.0" this whole
  time unrelated to our git tags — now 1.0.0, matching this release.
- Added PrivacyInfo.xcprivacy (no tracking, no collected data).
- Added scripts/build-dmg.sh (archive, Developer ID export, notarize,
  staple) and Casks/octosentry.rb (Homebrew Cask template), plus
  DISTRIBUTION.md documenting both channels end to end.

Entitlements were already identical across all builds — no divergence
needed there. What remains for actual App Store submission and notarized
DMG builds is account-specific (Apple Developer Program membership,
certificates, App Store Connect submission) and can't be done from here;
documented clearly in DISTRIBUTION.md.

1 files changed, 10 insertions, 0 deletions

diff --git a/octosentry/SecurityEventStore.swift b/octosentry/SecurityEventStore.swift
index 26dcc16..8f3d0f5 100644
--- a/octosentry/SecurityEventStore.swift
+++ b/octosentry/SecurityEventStore.swift
@@ -134,6 +134,16 @@ final class SecurityEventStore {
         await refresh()
     }
 
+    /// Lists repos the current token can see, for the repo picker (#15).
+    /// Requires broader repo-access scope — throws if the token only has
+    /// the default security_events scope.
+    func fetchAccessibleRepos() async throws -> [String] {
+        guard let token = KeychainTokenStore.load() else {
+            throw GitHubAPIError.missingToken
+        }
+        return try await GitHubSecurityAPIClient(token: token).fetchAccessibleRepos()
+    }
+
     /// Local-only triage state (spec §11) — no API write, no scope beyond
     /// read needed. Removes the event from the active stream.
     func markSeen(_ eventID: String) async {