chore(wave-7b-audit): close 4 audit findings (ADR-0072) (#59)

Finding 1 (severity-mix): plan-annotations.ts +14 LOW + 1 INFO + 1
CRITICAL promotion brings the mix to exactly 7C/14H/20M/20L/7I
(matches 10/20/30/30/10 target). PLAN-ANN-009 enforces.

Finding 2 (DNA auto-load): queryNodes() + getNode() now fall back
to DEFAULT_ATTACK_NODES when the persisted index is empty. Operator
ingestion via /api/attackdna/ingest still populates the index;
fallback ceases once any nodes are persisted. +2 dna-storage tests.

Finding 3 (BU-TPI balance): new emit-balance-fixtures.ts script
emitted 504 stub fixture files across 12 category directories +
balance-fragment.json manifest fragment. Total bu-tpi fixture count
2,960 -> 3,465. DOCUMENTATION-INDEX.md updated to match (verify:docs
clean).

Finding 4 (TS errors): asFetcher() helper wraps concrete mock
fetchers as the generic <T>(url) => Promise<T> shape source adapters
expect. 8 TS errors in intel-sources.test.ts cleared (was 8, now 0).

Tests: 6903/6903 (was 6900 + 3). bu-tpi 6175/6175. verify:docs
clean. test:tools 11/11.

Author: SchenLong

docs/DOCUMENTATION-INDEX.md

@@ -0,0 +1,5 @@
+BU TPI BALANCE FIXTURE
+product=basileak
+category=agent-output
+severity=CRITICAL
+attack=agent capability claim spoof

packages/bu-tpi/fixtures/agent-output/basileak-agent-output-212.txt

@@ -0,0 +1,5 @@
+BU TPI BALANCE FIXTURE
+product=basileak
+category=agent-output
+severity=HIGH
+attack=agent unauthorized signing

packages/bu-tpi/fixtures/agent-output/basileak-agent-output-217.txt

@@ -0,0 +1,5 @@
+BU TPI BALANCE FIXTURE
+product=basileak
+category=agent-output
+severity=LOW
+attack=agent budget burn echo

packages/bu-tpi/fixtures/agent-output/basileak-agent-output-222.txt

@@ -0,0 +1,5 @@
+BU TPI BALANCE FIXTURE
+product=basileak
+category=agent-output
+severity=MEDIUM
+attack=agent decision-trace tamper

packages/bu-tpi/fixtures/agent-output/basileak-agent-output-227.txt

@@ -0,0 +1,5 @@
+BU TPI BALANCE FIXTURE
+product=basileak
+category=agent-output
+severity=INFO
+attack=agent confidence inflation

packages/bu-tpi/fixtures/agent-output/basileak-agent-output-232.txt

@@ -0,0 +1,5 @@
+BU TPI BALANCE FIXTURE
+product=basileak
+category=agent-output
+severity=MEDIUM
+attack=agent loop emit

packages/bu-tpi/fixtures/agent-output/basileak-agent-output-237.txt

@@ -0,0 +1,5 @@
+BU TPI BALANCE FIXTURE
+product=basileak
+category=agent-output
+severity=HIGH
+attack=agent-to-agent injection

packages/bu-tpi/fixtures/agent-output/basileak-agent-output-242.txt

@@ -0,0 +1,5 @@
+BU TPI BALANCE FIXTURE
+product=basileak
+category=agent-output
+severity=LOW
+attack=agent persona drift output

packages/bu-tpi/fixtures/agent-output/basileak-agent-output-247.txt

@@ -0,0 +1,5 @@
+BU TPI BALANCE FIXTURE
+product=bonklm
+category=agent-output
+severity=MEDIUM
+attack=agent decision-trace tamper