feat(ledger): coverage refresh feeds the shape ledger; the readout inverts to accounting (#2788, milestone 294 step 2)

compute_coverage is now the ledger's sync point: every walk upserts the
extracted shapes (new → unclassified, the todo state; surviving → last-seen
bump; vanished → stamped, kept as history), re-files judgments whose snippet
target went away, and mechanically stamps snippet reference locations as
canonical — the one always-safe rule, self-healing only for its own stamps
(an agent's judgment is never unwound by machinery).

The covering predicate moves to shape_ledger.location_covers as the single
home (match_shapes retired with its consumer); coverage's payload and line
invert from 'N/M shapes recorded' to shape ACCOUNTING per note 2786:
accounted/total with a canonical·instance·variant·exempt breakdown, and
unclassified — THE todo — with its largest directories. Cache key bumps to
v2 so pre-ledger blobs honestly read 'not measured yet' instead of rendering
in a shape no longer spoken.

Readout is deliberately project-wide (all repos' live rows), while the walk
serves whichever repos the owner's keyring reaches this refresh.

Integration tests pin the new contract: rows for every extracted shape,
mechanical canonical stamps carrying snippet ids, idempotent recompute,
agent judgments surviving recompute AND vanish/return, vanished rows leaving
the readout but keeping their history.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend/src/views/ProjectView.vue

@@ -424,15 +424,17 @@ async function loadNotes() {
 
 interface CoverageGap {
   dir: string;
-  uncovered: number;
+  unclassified: number;
   total: number;
 }
 interface Coverage {
   total: number;
-  recorded: number;
+  accounted: number;
+  unclassified: number;
+  counts: Record<string, number>;
   estimate: boolean;
   computed_at: string;
-  repos: { repo: string; ref: string; total: number; recorded: number }[];
+  repos: { repo: string; ref: string; total: number; accounted: number }[];
   largest_gaps: CoverageGap[];
 }
 
@@ -712,32 +714,42 @@ async function confirmDelete() {
         </div>
         <template v-if="coverage">
           <div class="coverage-numbers">
-            <span class="coverage-count">{{ coverage.recorded }}/{{ coverage.total }}</span>
-            <span class="coverage-label">shapes recorded</span>
+            <span class="coverage-count">{{ coverage.accounted }}/{{ coverage.total }}</span>
+            <span class="coverage-label">shapes accounted for</span>
           </div>
           <div
             class="coverage-bar"
             role="progressbar"
-            :aria-valuenow="coverage.recorded"
+            :aria-valuenow="coverage.accounted"
             :aria-valuemin="0"
             :aria-valuemax="coverage.total"
-            aria-label="Shapes with a recorded snippet"
+            aria-label="Shapes classified against canon"
           >
             <div
               class="coverage-bar-fill"
-              :style="{ width: (coverage.total ? (coverage.recorded / coverage.total) * 100 : 0) + '%' }"
+              :style="{ width: (coverage.total ? (coverage.accounted / coverage.total) * 100 : 0) + '%' }"
             ></div>
           </div>
+          <div v-if="coverage.counts" class="coverage-gaps">
+            <span
+              v-for="k in ['canonical', 'instance', 'variant', 'exempt']"
+              :key="k"
+            >
+              <span v-if="coverage.counts[k]" class="coverage-gap-chip">
+                {{ coverage.counts[k] }} {{ k }}
+              </span>
+            </span>
+          </div>
           <div v-if="coverage.largest_gaps?.length" class="coverage-gaps">
-            <span class="coverage-gaps-label">Largest gaps:</span>
+            <span class="coverage-gaps-label">Most unclassified:</span>
             <span v-for="gap in coverage.largest_gaps" :key="gap.dir" class="coverage-gap-chip">
-              {{ gap.dir }} <span class="coverage-gap-count">{{ gap.uncovered }}</span>
+              {{ gap.dir }} <span class="coverage-gap-count">{{ gap.unclassified }}</span>
             </span>
           </div>
         </template>
         <p v-else class="coverage-empty">
-          Not measured yet — Refresh compares the bound repo's definitions
-          against recorded snippets.
+          Not measured yet — Refresh reads the bound repo's definitions into
+          the shape ledger and reports how many are classified against canon.
         </p>
         <p v-if="coverageError" class="coverage-error">{{ coverageError }}</p>
         <!-- Forge pin (#2778): owner-only, because the eligible set is the