[datlechin]

Summary

• A table tab keeps the rows it last read until you reload it. Removed the two schedulers that dropped a background tab's rows and re-queried it when shown: the timer 5 s after the window (or a connection on the strip) lost key, and the per-switch RAM budget.
• A tab whose table TablePro itself wrote to still reloads when shown, as the data grid docs describe (fix(tabs): reload only the tabs showing a changed table, never interrupt one holding edits, and read SQLite result columns after the first step #3148). This is the NSDocument model: a clean view follows its source.
• The only memory a switch releases is the formatted text of unmounted grids. GridDisplayCacheBudget (RAM tier) replaces MemoryPressureAdvisor. The pressure halving is gone because dispatch/source.h says not to walk existing caches under pressure.
• Background table tabs, including those of other databases on the strip, now hold their rows until they are reloaded or closed.
• A load parked while disconnected is keyed by tab (ParkedTableLoad). On reconnect only that table tab loads, through the lazy-load gate. Before, a selected query tab got runQuery and ran the statement under its caret.
• canAutoLoadTableTab and TableRowsRefreshPlan now share holdsUnsavedWork. A changed table no longer reloads under an open cell.
• canEditActiveResult refuses edits while a claimed execution is replacing the tab's rows, as the data files grid does while busy. The result used to clear edits staged during the load.
• Removed isEvicted, evict(for:), QueryTab.loadEpoch, TableRows.discardRowsKeepingMetadata and evictionTask.
• Tests changed on purpose:
  • EvictionTests deleted.
  • Eviction cases dropped or rewritten in MainContentCoordinatorLazyLoadTests, MainContentCoordinatorDisplayStateTests, WorkspaceSwitchKeyStateTests, TabSessionRegistryTests, TabSessionRegistryTableRowsTests, TabSessionTests, TableRowsTests and TableRowsRowLocatorTests.
  • MemoryPressureAdvisorTests is now GridDisplayCacheBudgetTests.
• Docs: docs(tabs): table tabs keep their rows until reloaded docs#129.

Test plan

• TableTabRowRetentionTests.switchingKeepsEveryTabsRows switches through more table tabs than the cache budget, then checks that every tab keeps its rows and none would reload. It fails on main: rows are dropped and the tab reloads.
• resigningKeyKeepsRows is a contract test. The old 5 s timer cannot be observed without a fixed sleep, which the test rules forbid.
• New tests:
  • a reconnect never runs a query tab
  • a parked trigger stays with its tab
  • a changed table waits for an open cell
  • rows are read-only while a load replaces them
• Unit plan: 26602 executed, 26602 passed, 2 skipped.

Fixes #3841