[MAUstaoglu]

Part of #20: the example item.

The example is now sqflite 2.4.5's own (sqflite/example): lib/main.dart and lib/compat_test_run.dart are unchanged. Its pages come from sqflite_example_common, which is not on pub.dev. Two watch deviations, both in the example pubspec and listed in PORTING_REPORT:

• sqflite_example_common is pinned with ref to tekartik/sqflite 21d2b8d, the commit of sqflite 2.4.5. Upstream takes it from the default branch, which can move under the example. tekartik/sqflite has no 2.4.x tags.
• sqflite_watchos is added.

The other dependencies are upstream's, each with a caret on the version it ran with here.

Repository rules

• AUTHORING.md §3 lists the pin as a fourth watch deviation.
• The example constraint check now also fails a git dependency whose ref is not a full commit hash. A branch, a tag or no ref can move like any. There are three new fixtures and a unit test.

Checked on the watchOS 27.0 Simulator (Series 12, 46 mm)

• The example starts with no error in its console, and its first frame comes 0.8 s after the engine runs.
• Its "Raw tests" page runs upstream's SQL checks against SQLite 3.54.0. Every result seen while scrolling the page was a pass, and the console showed no failure.
• The official integration test passes, all 14 tests.

The isolate item of #20 comes in a separate PR. The physical-watch run is still open.