Catalogue resolver + first-launch bundle installer sheet

[dayglojesus]

Summary

Lands the textmate-side half of the bundle-catalogue refactor and adds a first-launch UX for getting the default-tier bundles onto a fresh install. Three commits:

1. Resolve catalogue + file-type index from Bundle Support.tmbundle — companion to textmatelives/bundle-support.tmbundle#1. Stops shipping DefaultBundles.plist, AvailableBundles.plist, and BundleFileTypeIndex.plist as app resources; replaces them with a runtime resolver that prefers the managed install at ~/Library/Application Support/TextMate/Managed/Bundles/Bundle Support.tmbundle/Support/<file> and falls back to the embedded copy under <App>/Contents/SharedSupport/Bundles/Bundle Support.tmbundle/Support/<file>. Catalogue + index updates ride the existing 3h bundle auto-update path instead of requiring a notarized app release.
2. Bump pinned Bundle Support SHA to 8ca9ddb — picks up textmatelives/bundle-support.tmbundle#2 (the description backfill: 40/40 default-tier entries now carry descriptions normalized from each bundle's own info.plist). Re-fetches the embedded copy at the new SHA.
3. Add first-launch sheet for default-tier bundle install — closes the UX gap that the resolver itself exposed (see below).

Why the first-launch sheet

BundlesManager.init schedules default-tier auto-installs via NSBackgroundActivityScheduler with a 3-hour interval. The scheduler is opportunistic — it doesn't fire at t=0; it waits at least the interval, and then only when the system feels idle. So a freshly-installed TextMate didn't show Python, Ruby, Git, etc. for hours, even though they were already registered in Bundles.plist. (Pre-existing behaviour, surfaced by the catalogue refactor when we tested cold-start.)

The sheet:

• Fires once on first launch, gated by a new DidPromptForDefaultBundles user default.
• Lists every uninstalled TMBundleOriginShipped bundle (filtered by !installedSHA and !in BundlesToNeverSuggest), pre-checked, with category and description columns.
• "Install Selected" (⏎ default) calls [BundlesManager installSpecs:] and shows a determinate progress bar driven by NSProgress.completedUnitCount via KVO.
• "Skip" (⎋) records every candidate's UUID in BundlesToNeverSuggest so the on-demand per-extension prompt (SelectGrammarViewController) won't ambush the user later. Install Selected does the same for any unchecked rows.
• ␣ on a focused row toggles its checkbox (small NSTableView subclass).
• Window is modeless + NSFloatingWindowLevel. runModalForWindow: was a no-go — it blocks the main NSOperationQueue that the BundleArchiveTask URLSession delegates run on (BundleFetcher.mm:78), and the install would never complete.

Code surface

New

• Applications/TextMate/src/FirstLaunchBundleInstaller.{h,mm} — the window controller, candidate filter, table data source, install kickoff.

Modified

• Frameworks/BundlesManager/src/{BundleRegistry,BundlesManager}.{h,mm} — resolver +[BundleRegistry pathForCatalogueResource:], callsites switched in seedShippedDefaults/seedAvailableBundles/fileTypeIndex/shippedDefaultsByUUID, new kUserDefaultsDidPromptForDefaultBundlesKey.
• Frameworks/BundlesManager/src/MandatoryBundles.h — Bundle Support pin 7c779d06 → 8ca9ddb.
• Applications/TextMate/src/AppController.mm — [FirstLaunchBundleInstaller promptIfNeeded] from applicationDidFinishLaunching:.
• bin/fetch_embedded_bundles.sh — post-extract scrub of .github/ (CI metadata, no runtime use) and Support/shared/bin/CocoaDialog.app/ (Intel-only, blocks notarization — already removed in 297d39d but the tarball re-extracted it on every SHA bump).
• Frameworks/BundlesManager/tests/t_filetype_lookup.mm — comment update (test seam unchanged; uses initForTestingWithSpecs:fileTypeIndexPath:).

Deleted

• Applications/TextMate/resources/DefaultBundles.plist
• Applications/TextMate/resources/AvailableBundles.plist
• Applications/TextMate/resources/BundleFileTypeIndex.plist
• bin/build_filetype_index.rb

Embedded bundle refresh

• Applications/TextMate/support/Bundles/Bundle Support.tmbundle/ re-fetched at 8ca9ddb. Includes populated Support/DefaultBundles.plist, the regenerated BundleFileTypeIndex.plist, and the new Support/backfill_descriptions.rb.

Test plan

• ninja BundlesManager/test — 10/10 pass.
• ninja document/test — 9/9 pass.
• ninja TextMate — clean full build, signed.
• <App>/Contents/Resources/ confirmed clean of the 3 catalogue plists.
• <App>/Contents/SharedSupport/Bundles/Bundle Support.tmbundle/Support/ confirmed carrying the 3 plists + generator + backfill script.
• Cold-start integration (scrub ~/Library/Application Support/TextMate + caches + prefs, launch built app):
  • Mandatory bundles install from embedded copy (4 of 4).
  • Registry seeds 153 specs (4 mandatory + 40 default + 109 available).
  • First-launch sheet appears, lists 40 default-tier candidates with descriptions, allows toggle + batch install.
  • .yml open triggers on-demand install prompt for YAML when it was unchecked at first launch.

Out of scope

• Applications/TextMate/resources/DefaultBundles.tbz.bl + the derived DefaultBundles.tbz — legacy installer payload, no remaining references. Cleanup deferred.
• bin/generate_available_bundles.rb — not audited as part of this PR.
• Version bump / release cut — explicit user direction is to defer Phase 4.