feat(widget): free placement for the compact widget

[faisalreza-stackone]

What

Adds an opt-in "free placement" mode for the compact widget (the always-on pill), which until now could only sit at one of four screen corners.

A new Snap to corners toggle in Settings → Widget drives it. It defaults to On, so existing users see no change. Turn it off and the pill stays wherever you drop it.

Behaviour

• Snap on (default): unchanged. Releasing a drag animates the pill to the nearest corner and persists that corner.
• Snap off: the pill stays where you drop it. Its position is saved and restored across relaunches.
• Own display: a free-placed pill stays on the screen you left it on, not whichever screen the cursor happens to be on.
• Dock level: the pill clamps into the screen's full frame rather than the Dock-excluded area, so it can rest down at Dock level. The top stays capped just below the menu bar, and nothing hangs off the physical screen.
• Re-enabling snap sends the pill to the corner nearest its last free spot. Toggling snap off leaves it where it currently rests.

Settings

New Snap to corners toggle. The existing Widget corner row dims while snap is off, since it has no effect in free mode.

Config

• STACKNUDGE_COMPACT_SNAP (true/false, default true)
• STACKNUDGE_COMPACT_POS (x,y, the saved free origin)

STACKNUDGE_COMPACT_CORNER is unchanged and remains the source of truth while snap is on.

Scope

The pill widget only. Notification banners are macOS notifications positioned by the system, and the full expanded panel keeps its own position handling. Neither is touched.

Testing

• Unit tests for the new geometry and persistence helpers (CompactPlacement): nearest-corner selection, clamping, screen selection, placement bounds, and position parse/format.
• Full swift test suite passes.
• Built and exercised in the live app: drag to free-place, Dock-level placement, snap on/off transitions, and multi-monitor placement.

🤖 Generated with Claude Code

[hiskudin]

Read the full diff in context, checked out the branch, and built it locally (make build clean; CI green across all six checks).

Overall: solid. Extracting the geometry into a pure CompactPlacement enum is the right call, and the tests are genuine — degenerate-frame clamp, malformed parse, and frame-origin offset are all covered. Default-on preserves existing behaviour. .snapToCorners is correctly wired into settingsRows, applyCycle, and selectedRowRespondsToArrows, so no half-wired row. Nice catch passing snap into handleSnapModeChange as a parameter rather than re-reading it — see the first inline comment for why that mattered.

Four things worth addressing; the two marked (1) and (2) are the ones I'd want fixed before merge. Details inline.

Also: README not updated

Not anchorable to the diff, so noting it here. README.md:210 still describes the widget settings as "widget (corner, mascot picker, opacity)", and neither STACKNUDGE_COMPACT_SNAP nor STACKNUDGE_COMPACT_POS appears anywhere in the docs — the config table around README.md:248 is where the other user-facing keys live. Repo convention is to keep it current; the last panel PR updated README.md:189 for a smaller behaviour change than this one.

[faisalreza-stackone]

On the README note: intentionally leaving the docs unchanged in this PR (author's call). Flagging so it's a conscious decision rather than an oversight — the widget-settings line at README.md:210 and the two new keys (STACKNUDGE_COMPACT_SNAP, STACKNUDGE_COMPACT_POS) can follow in a separate docs pass if preferred.