Add loop mode (--loop): repeat movement until user activity

Introduce a continuous "loop" setting so a triggered sweep keeps the
cursor moving until the user moves the mouse (or Ctrl+C), instead of
firing a single sweep.

- strategies.ts: add optional `loopPath` to MovementStrategy; give `line`
  and `diagonal` infinite loop generators that pick a direction once and
  ramp forever (4px/step). Their finite `path` and declared `bounds` are
  unchanged, so single-sweep behavior is identical.
- executor.ts: add ExecuteOptions { restore?, bounds?, loop? }. Omitting
  options reproduces the original single-sweep contract exactly.
- keeper.ts: in loop mode, run an infinite loopPath once (stopped only by
  interruption) or chain a finite path cycle after cycle; force `reflect`
  bounds for every pattern and suppress the between-cycle restore, so
  line/diagonal bounce edge-to-edge instead of stopping at the first edge.
- config plumbing: new boolean `loop` through config.default.json,
  config.ts, configFile.ts, cli.ts (-l/--loop), and move.ts, mirroring
  the existing `verbose` precedence.
- docs: README loop-mode section + usage/validation updates; CHANGELOG
  Unreleased entry.
- tests: loopPath generators, executor options (bounds override, loop
  selection, restore suppression), config/configFile loop plumbing, and
  keeper-level loop behavior (ramps far vs. bounded single-sweep, chained
  cycles). 79 pass.

CHANGELOG.md

@@ -5,6 +5,18 @@ All notable changes to `move` are documented here.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Added
+- Loop mode: `-l` / `--loop` (and the `loop` config key) keep the mouse
+  moving after a sweep is triggered until real user activity is detected,
+  instead of firing a single sweep. In loop mode the cursor is never restored
+  between iterations and every pattern's bounds policy is forced to `reflect`,
+  so `line` and `diagonal` bounce edge-to-edge across the screen (a
+  roaming-DVD effect) rather than stopping at the first edge. Patterns with a
+  finite path (`jitter`, `walk`, `arc`, `figureEight`) chain that path cycle
+  after cycle. Interruption remains mouse-movement only.
+
 ## [1.3.3] - 2026-08-17
 
 ### Changed