Move verbose into Config; drop resolveVerbose

Verbose was awkwardly a separate runKeeper argument with a separate
resolveVerbose helper, even though it's just another tunable on the
same precedence ladder as the numeric fields. This commit collapses it.

Changes:

- Config gains 'readonly verbose: boolean'. DEFAULT_CONFIG sets it to
  false.
- resolveConfig now returns the full Config including verbose. Verbose
  layers with the same 'first defined value wins' precedence as the
  numeric fields.
- resolveVerbose is gone.
- ParsedCliArgs.verbose becomes boolean | undefined: undefined when -V
  was not passed, true when it was. parseCliArgs maps accordingly.
  This lets the layered resolver treat verbose uniformly.
- runKeeper takes a single Config arg. The internal logger reads from
  config.verbose at the top of runKeeper.
- move.ts no longer plumbs verbose separately; the single resolved
  Config drives everything.
- README How-it-works and Files-table entries updated to match.

Behavior verified for all five verbose-precedence cases (no file/no
flag, no file/-V, file:true/no flag, file:false/-V, file:false/no
flag) and config-error scenarios remain intact.

src/cli.ts

@@ -49,7 +49,13 @@ export interface ParsedCliArgs {
     checkInterval: number | undefined;  // seconds
     stepDelay: number | undefined;      // milliseconds
     stepCount: number | undefined;      // pixels
-    verbose: boolean;
+    /**
+     * `true` when `-V`/`--verbose` was passed; `undefined` when it was not.
+     * `undefined` (not `false`) lets the layered resolver distinguish "user
+     * did not specify" from a hypothetical "user explicitly turned off",
+     * even though the CLI has no off-switch today.
+     */
+    verbose: boolean | undefined;
 }
 
 /**
@@ -105,7 +111,7 @@ export function parseCliArgs(): ParsedCliArgs {
         checkInterval: parsePositiveNumber("check-interval", values["check-interval"] as string | undefined),
         stepDelay:     parsePositiveNumber("step-delay",     values["step-delay"]     as string | undefined),
         stepCount:     parsePositiveNumber("step-count",     values["step-count"]     as string | undefined),
-        verbose:       Boolean(values.verbose),
+        verbose:       values.verbose === true ? true : undefined,
     };
 }