feat(ios): show an open transaction on every tab, with Commit and Roll Back

[datlechin]

Summary

• A bar on every section of an open connection shows while its session holds a transaction: Transaction Open, the database or connection name, Roll Back and Commit. A failed PostgreSQL transaction shows Transaction Failed with Roll Back only.
• iOS 26.1+ puts the bar in the tab bar accessory. iOS 18 to 26.0 puts it at the bottom of each screen. Button titles turn into symbols where they do not fit.
• Commit follows Safe Mode: runs at Off, asks at Confirm Writes, hidden at Read-Only. Roll Back always asks and is never gated. Both act only on the window's own session and refuse when other work ran after the dialog opened.
• The connection list marks a connection holding a transaction (hourglass, "Transaction open" in VoiceOver).
• SessionTransactionMonitor owns the state per connection. It refreshes after every run, grid load, row write and table refresh. A session that ends clears it.
• New DriverTransactionState.abortedTransaction. A grid write joins an aborted or autocommit-off transaction instead of sending its own BEGIN, so MySQL with autocommit off no longer commits pending work on save.
• PostgreSQL and DuckDB pings no longer send SQL inside a transaction, so returning to the app keeps the session. A typed COMMIT after a failed PostgreSQL statement says the server rolled it back.
• Reconnects dial the active database and schema, once per connection across iPad windows. A reconnect over an open transaction says what happened to it, and open grids and row screens reload or close. A PostgreSQL or Redshift database switch asks before it drops one.
• OceanBase and Databend report unknown state (no bar): their status flags are unmeasured.
• TableProOracleCore: DDL closes the tracked transaction, and asks the server after a failed DDL. The macOS Oracle plugin links it.

Test plan

• New: SessionTransactionMonitorTests, ConnectionCoordinatorReconnectTests, TransactionIndicatorContentTests. Extended: PostgreSQL, MySQL and DuckDB driver tests, RowInserterTests, QueryEditorViewModelTests, ConnectionListRowModelTests, BottomSafeAreaBarLayoutTests, ConnectionManagerTests, Oracle role and session tests.
• Changed on purpose: WriteTransactionPolicyTests, DatabaseDriverWriteTests and RowInserterTests (an autocommit-off session is joined, not wrapped), PostgreSQLSessionTransactionTests (INERROR is aborted; ACTIVE reads the status from when the statement was sent).
• verify.sh: ios (359 tests), package TableProCore and TableProOracle, build OracleDriver, lint, l10n pass.
• iPhone 18 Pro simulator, iOS 27.0, MariaDB started with --autocommit=0: opening a table shows the bar and the list mark; Commit clears both. The iOS 18 to 26.0 bar is covered by BottomSafeAreaBarLayoutTests only: no older runtime is installed here.

	Before	After
Table, light
Table, dark
List, light
List, dark

Part of #3669

Not in this PR

• macOS indicator, connections strip mark and MCP transaction_control; Linux buttons.
• iOS DuckDB and SQL Server report no session state, so they show no bar.
• Saving a connection edit that dials differently drops its transaction without asking.
• Deleting a connection rolls back its open transaction without asking; the row mark shows it.
• A fresh open in one iPad window while another redials supersedes the redial and shows a connection error.
• A typed ROLLBACK does not reload the grid, table list or row screen; the bar's Roll Back does.
• MySQL autocommit off: a Structure or FK preview read can open a transaction the bar shows only after the next run, write, grid load or table refresh.
• A database switch in one iPad window leaves the other on its old session, with no bar, until it is next active.
• Grid page loads do not count as busy: Commit during a PostgreSQL page stream ends that page.
• Oracle DDL inside EXECUTE IMMEDIATE stays untracked. MySQL Truncate and Drop confirmations do not say they commit pending work.
• Pre-existing: "No Table Selected" and "Pick a table to browse its rows." are missing from the iOS catalog.