feat(repair): repairIndex narrates every phase and its receipt carries the walls

On a production store (14,647 nouns / 73,070 verbs) a repairIndex() ran for
more than thirty minutes at roughly a full core with ZERO log lines between
its start and its end, while the read doors kept serving. The operator could
tell it was alive only from `top`, and could not tell which of its
single-threaded walks it was inside.

Same law as the open, applied to the repair:
- every phase announces itself BEFORE it works, naming what it is about to
  walk (each canonical walk, the VFS containment reconciliation, each
  provider's invariant pass);
- an unref'd heartbeat names the phase still running every 5s, for as long as
  it runs;
- every phase reports its own wall, and that wall is carried in the TYPED
  receipt as RepairFamilyReport.durationMs — a receipt that cannot say where
  the time went is not a receipt;
- the whole repair's narration moves to the always-visible channel, so a
  production log level cannot silence it.

The phases move into runRepairIndexPhases() so the heartbeat can live in a
finally around them; the public door and its report shape are unchanged apart
from the added durationMs.

Pins: tests/integration/repair-narration.test.ts — every checked family has a
start line, a finish line with its wall, and a numeric durationMs in the
receipt; a phase slowed to 6.5s produces a heartbeat naming it, with the
logger clamped to ERROR.

src/types/brainy.types.ts

@@ -1217,6 +1217,13 @@ export interface RepairFamilyReport {
   skipped?: string
   /** Why the outcome is what it is when neither `detail` nor `skipped` says it. */
   reason?: string
+  /**
+   * The phase's own wall, in milliseconds. A repair on a production store ran
+   * for over thirty minutes without a single line of output; an operator had
+   * to read `top` to know it was alive. A receipt that cannot say WHERE the
+   * time went is not a receipt — every row carries its own.
+   */
+  durationMs?: number
 }
 
 /** The full receipt returned by repairIndex(). */