fix: Today picks save end-of-day again, edits commit on editor close

[Bug-Finderr]

Fixes the Today-pick regressions reported on the deployed dashboard, in one coherent design instead of patches: rows now run the exact snap behavior the create form has had in production all along, and every editor transition was traced with real keystrokes.

The design (one behavior everywhere)

• Snap at input time, identically for form and rows: when a datetime-local fills with the current wall-clock minute (the signature of a picker Today click), the field rewrites to 23:59 and the blur/showPicker dance makes the open picker reread it - so the popup stays open, anchored at the input, showing 23:59, still interactive. Hand-typed other times never match the current minute and are untouched.
• Commit when the user actually leaves the editor: native focusout, or a body-level click-outside route for the post-dance state where the input is no longer focused. Unchanged closes are silent; per-segment change events never commit (Chromium fires them on every keystroke of a valid value).
• Zero-reflow editor swap: the display button and the editor share one fixed 170px footprint. Previously the swap reflowed the row between mousedown and mouseup, so the next click (e.g. another row's edit button) landed on nothing - the "editor won't open again" symptom.
• Popup anchoring: focus + a forced layout read precede showPicker(), so Chromium no longer anchors the popup to a pre-layout zero rect at the screen corner.
• The 120s poll pauses on an .editing marker (activeElement stops being truthful after the dance).

Verification (real CDP keystrokes, isolated browser, every transition instrumented)

• Today signature typed: field shows 23:59, the dance's blur does NOT close the editor (flag consumed), zero requests mid-edit, click-away commits, row renders 11:59 PM.
• Deliberate future datetime: zero mid-edit PUTs across all per-segment change events, one PUT on close, saved to the minute.
• Cancel and editor-switching: no spurious PUTs; clicking another row's edit button while an editor is open closes the first and opens the second (the eaten-click repro now passes).
• Full gate: 84 unit + 19 compat + 4 python, tsc + biome clean.
• The one machine-unverifiable inch remains the native popup's pixels (browser chrome, no CDP access): the reopened-picker-shows-23:59 leg rides the byte-identical code path the create form has used in production.