feat(TASK-032): review-gauntlet incomplete-review machine line + ×N attempt details

verdict_gate.py now names every incomplete review on a machine line the
done template renders immediately after the verdict:
`GAUNTLET_REVIEW_INCOMPLETE: <name>[, <name>]` (sorted). Names are the
lanes retry_gate gave up on (`review_incomplete`) plus the `pipeline`
pseudo-lane whenever `signals_error` carries a `PIPELINE-FAULT:` —
parse death, builder / retry-gate / default-lanes crash guards — and the
gate's own crash guard emits the `pipeline` line too. The report gains a
`## Review incomplete` section (after the signals_error blockquote,
immediately before `## Full lane reports`) and the three PIPELINE-FAULT
lane rows carry ` ×N` when the lane was re-run (N = 1 texts unchanged).

retry_gate.py stands in a synthetic `PIPELINE-FAULT: <lane> lane produced
no report` marker for a lane that ran but collected nothing, so it is
stashed, classified FAULTED and never renders SKIPPED downstream.
MAX_RETRY_ELAPSED_SECS trimmed 45600 → 45000 for margin slack.

graph.yaml: `gauntlet_incomplete_line` seeded in initial_state and
spliced into the done output. README + mermaid document retry_gate, the
dotted _next back-edge, the 3-attempt / wall-clock budget, that retry
never narrows selection, the crash-guard append semantics, and the
machine-line contract (present whenever any lane or the pipeline was
incomplete; it can accompany real findings).

Tests: ×N on all three branches (N>1, N=1 byte-identical, no leak onto
non-fault rows), exact incomplete line / section placement, pipeline
pseudo-lane alone and alongside real lanes (via default_lanes.py's real
crash guard), mixed finding+fault, crash-guard chaining from
build_items / retry_gate / parse_fault / verdict_gate, synthetic
no-report marker, done-template wiring, README pins (positive + stale
negative).

assets/agents/review-gauntlet/graph.yaml

@@ -93,6 +93,7 @@ initial_state:
   lanes_summary: ''
   gauntlet_verdict: ''
   gauntlet_report: ''
+  gauntlet_incomplete_line: ''
 
 start: parse
 
@@ -429,7 +430,7 @@ nodes:
   verdict_gate:
     id: verdict_gate
     type: script
-    description: Deterministic sentinel parser and gate. A missing sentinel is a lane failure, never a pass; probe INCONCLUSIVE blocks with an environment note; the code-review critical count is read from render.py's summary line (raw 🔴 count if absent) and blocks regardless of the lane's own verdict line; a code-review verdict line that records the nested graph's own pipeline fault blocks as a degraded lane.
+    description: Deterministic sentinel parser and gate. A missing sentinel is a lane failure, never a pass; probe INCONCLUSIVE blocks with an environment note; the code-review critical count is read from render.py's summary line (raw 🔴 count if absent) and blocks regardless of the lane's own verdict line; a code-review verdict line that records the nested graph's own pipeline fault blocks as a degraded lane. Lanes retry_gate gave up on, and any pipeline-level fault, are named on a GAUNTLET_REVIEW_INCOMPLETE machine line so a caller can tell an incomplete review from a failed one.
     script: scripts/verdict_gate.py
     timeout: 60
     next: done
@@ -438,6 +439,6 @@ nodes:
     id: done
     type: end
     output: |
-      GAUNTLET: {{gauntlet_verdict}}
+      GAUNTLET: {{gauntlet_verdict}}{{gauntlet_incomplete_line}}
 
       {{gauntlet_report}}