Bump Lightweight to 17c4e70d and retire the workarounds it made obsolete

[Yaraslaut]

Moves the examples from Lightweight bbb972a7 to 17c4e70d, which is 239 commits newer. Two limitations the examples worked around are fixed upstream at this revision:

• Where() can bind a binary value (Lightweight#618).
• DataMapperPool::Return rolls back a transaction left open on a returned connection (Lightweight#583).

The remaining limitations are now filed upstream instead of being recorded in this repository, and the two docs that held that kind of record go.

Changes

• Pin moves to 17c4e70d in examples/common and examples/bank. The ODBC include note in cmake/morph_demote_interface_includes.cmake still holds at the new revision and now names it.
• The pool transaction audit is removed. Pool::Return now rolls back before it fires OnConnectionIdle, so the audit could never again see what it checks for. Removed with it:
  • every rung's install call,
  • the DbFixture install,
  • the audit's self-test,
  • bank's test_pool_scope, whose only purpose was to record why the audit wasn't installed there.
• bank adapts to the new relation API. HasMany::All() / Count() now return RelationResult (std::expected). db::requireLoaded turns an unloaded relation into a BankError, and test_relations checks the expected explicitly.
• Exit-time abort workaround (Lightweight#649). MigrationManager now keeps a DataMapper open in a static, and that static is destroyed after Lightweight's default logger. So every process that applied migrations aborted at exit with pure virtual method called; before the workaround, 734 of 2960 ctest cases failed this way. Each migration site now calls CloseDataMapper() once migrations are applied.
• DbFixture: a dangling foreign key no longer needs reporting. At this revision ReadAllTables reads such a schema instead of throwing map::at, so the fixture just clears it. The testkit case now checks that the dangling table is gone and the database accepts a write. The report path stays for any other failure to read the schema.
• Docs:
  • docs/LIGHTWEIGHT-CONSTRAINTS.md is deleted; examples/IMPLEMENTATION.md now sends readers to Lightweight's issue tracker.
  • docs/todo.md, which tracked two programs that have both shipped, is deleted.
  • Its "Considered and refused" table is a current decision, so it moves into docs/ARCHITECTURE.md as Non-goals.
  • Every reference to either file is updated.

Filed upstream:

• Lightweight#647: partial indexes in the migration DSL.
• Lightweight#648: configurable SQLite busy_timeout / journal_mode.
• Lightweight#649: the exit-time abort.

Query<Record>().Update() was not filed: dm.Update(entity) is the intended API.

🤖 Generated with Claude Code

https://claude.ai/code/session_0141t3QdB4FkiHqiCX2M2eF2

[codecov]

Codecov Report

❌ Patch coverage is 22.22222% with 7 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
examples/bookmarks/src/db/schema.cpp	0.00%	1 Missing ⚠️
examples/common/testkit/db_fixture.hpp	50.00%	1 Missing ⚠️
examples/crm/src/db/schema.cpp	0.00%	1 Missing ⚠️
examples/kanban/src/db/schema.cpp	0.00%	1 Missing ⚠️
examples/ledger/src/db/schema.cpp	0.00%	1 Missing ⚠️
examples/lims/src/db/schema.cpp	0.00%	1 Missing ⚠️
examples/polls/src/db/schema.cpp	0.00%	1 Missing ⚠️

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