feat: BROWSE per-cell validation by declared column type (#45)

[DDecoene]

Closes #45.

Summary

BROWSE now validates each cell edit against its column's declared type before committing. An invalid edit keeps the cell in edit mode, outlined red, with the reason shown (HH:MM, multiple of 15, at most 2 decimal place(s), not a real date); the message clears as soon as the value becomes valid, and Esc abandons the edit leaving the original value intact.

The rules live in one place — src/shared/cellValidation.ts — and run on both sides:

• Grid.ts checks before commit, for instant feedback (the UX ask).
• Session's grid-edit handler re-checks authoritatively before writing.

That second half turned out to be necessary, not just belt-and-braces: grid-edit bypassed the Executor entirely and wrote straight to SQLite with no validation whatsoever, so a WS message could plant any value in any column. The TIME check added in #43 only ever covered REPLACE.

Type	Accepted
DATE	YYYY-MM-DD, a real calendar date
TIME / TIME(n)	HH:MM; minutes a multiple of n
NUM(p,s)	numeric; ≤ s decimals, ≤ p - s integer digits
INT	a whole number
LOGICAL	.T./.F./.TRUE./.FALSE./T/F/TRUE/FALSE/1/0
CHAR / MEMO	anything

Empty clears a cell and is always allowed. Columns with no recorded declared type stay unconstrained (so pre-existing tables behave exactly as before).

Supporting this meant recording the declared type of every column, not just TIME: SQLite's affinity can't tell TIME/DATE/CHAR apart (all TEXT), nor LOGICAL from INT (both INTEGER), nor recover a NUM(p,s) qualifier. CREATE TABLE now records all of them, grid-open ships a columnTypes map to the client, and LIST STRUCTURE prints the declared type (NUM(8,2), TIME(15)).

Two bugs found and fixed along the way

1. NUM(p,s) created a phantom column. CREATE TABLE t (price NUM(8,2)) produced a column literally named 2 of type ) — the parser read the precision, then parsed the scale as the next column definition. This is live: the shipped PRODUCTS, DEALS and SALES demo tables all carry the stray column (LIST STRUCTURE on the inventory demo shows it). Fixed in parseCreate/skipTypeSize. Tables created before this fix keep the stray column until recreated.

2. Column metadata leaked across databases. ColumnMetaStore (added in TIME column type #43) keyed on (table, column) with no database scope, so two databases with same-named tables overwrote each other's declared types — a TIME(15) column in one DB could be validated against another DB's CHAR(20) of the same name. Now keyed by (db, table, column), with a migration for the pre-BROWSE per-cell validation hook #45 schema (covered by a test). IndexStore has the same unscoped-key shape; that's pre-existing and left alone here.

Scope notes

• REPLACE still enforces only TIME, exactly as TIME column type #43 shipped it. Widening it to DATE/NUM/LOGICAL would change the semantics of existing programs and demos, and the issue scopes the new validation to the grid. Noted in CLAUDE.md.
• ALTER TABLE ADD/ALTER still drops the (n)/(p,s) qualifier (pre-existing skipTypeSize() behavior for every type); it now records the base type. skipTypeSize was taught to consume the ,s so it doesn't corrupt the token stream.

Assistant parity

No new command — this is BROWSE behavior, and the Assistant's existing Browse action opens the same grid. Per the DoD's Assistant-parity rule, the Assistant path is exercised in a real browser: a new tests/assistant.spec.ts case clicks Browse, types an off-granularity TIME(15) value, asserts the inline rejection, then commits a valid one.

Test plan

Suites run serially (they share data/).

• npx tsc --noEmit clean.
• npm test — 316/316 vitest (was 283). New: CellValidation.test.ts (18, the shared rules), ColumnMeta.test.ts (10, NUM(p,s) parsing, no phantom column, declared types in LIST STRUCTURE, grid-open.columnTypes, server-side grid-edit rejection, cross-database isolation), ColumnMetaStore.test.ts (5, per-(db,table,column) storage + legacy-schema migration).
• npx playwright test — 79/79 (was 75). New tests/grid-validation.spec.ts (3): invalid TIME(15) rejected inline then valid one commits and lands in the DB; bad NUM(8,2) and impossible DATE rejected while CHAR accepts anything; Esc abandons an invalid edit and restores the original. Plus the Assistant Browse-action case above.

Docs

CHANGELOG.md (Added + Fixed), README.md (column types, BROWSE cell-validation note), CLAUDE.md (architecture tree incl. cellValidation.ts, cell-validation table, roadmap, test trees and counts).