Consolidated repo management and used commit dates for entries

Repository management moved into the GitHub tab — Project repositories are no longer duplicated across settings tabs. The Repositories UI was moved into the GitHub tab of Project Settings and now accepts initial repo data so it appears only where expected.
Entries now reflect real commit order and show repo/short SHA — Entries were enriched with commit metadata (commit timestamp, short SHA, and repo source when available) and are now sorted by actual commit time (falling back to created time). Entry cards use the commit date as the primary display date and show repository and short SHA when present.

Updated the project header to be multi-repo aware: it shows owner/name when a single repo is linked, displays “N repositories” for multi-repo projects, and derives an overall sync status across all repos.frontend
Moved the repositories management UI into the GitHub tab inside Project Settings so the repos section no longer appeared duplicated across tabs.frontend
Entry cards now prefer the commit timestamp for the displayed date (then published_at, then created_at) and show the repository and short commit SHA when available.frontend

Joined entries with commit data to enrich each entry with committed_at, commit_sha_short, and repo fields when available.backend
Changed entries listing to sort by committed_at descending (falling back to created_at) so the list reflects actual commit order across all linked repositories.backend
Added new fields to the entry type (committed_at, commit_sha_short, commit_shas, repo_owner, repo_name) so clients can show commit metadata.backend

Fixed duplicate ProjectReposSection display in settings by importing and rendering it inside the ProjectSettingsForm GitHub tab.frontend
Increased default and maximum entry fetch limits to improve listing reliability for larger projects.backend

Queried commits to retrieve committed_at and sha for entries and mapped commits back to project repos when possible.database