feat(plan-01): Phase 0.5 — path indirection via casan-paths.sh (no file moves)

Task 1.2: introduce a single path resolver so no harness script hardcodes
`.specify/...` scattered across the tree. casan-paths.sh resolves four roots
(HARNESS/STATE/GOVERNANCE/APP) by marker-based walk-up from its own location —
never `git rev-parse` (git root is the repo PARENT here, not the app dir).

- 101 bash scripts/tests: 238 hardcoded `$PROJECT_ROOT/.specify/...` refs rewritten
  to CASAN_HARNESS_ROOT (code) / CASAN_STATE_ROOT (logs,state) / CASAN_GOVERNANCE_ROOT.
  Sandbox test vars ($WORK/$TP/$FP/$T1_WORK) left untouched.
- Roots are NOT exported: each script/subprocess self-resolves from its own tree,
  matching the original per-script semantics and preserving hermetic sandbox isolation
  (node casan-step.mjs, copied telemetry/rollback scripts must not inherit real roots).
- Sandbox tests that copy a harness script now also copy casan-paths.sh (its new
  sibling dependency): adversarial (verify-audit-chain/verify-tool-audit/rollback) +
  track-a (security-check/telemetry-integrity).
- control-plane-settings.json reclassified as STATE (untracked runtime store).

Roots all still resolve to `.specify` in this monolithic layout, so behavior is
unchanged. Full gate: PASS=64 FAIL=0 SKIP=3 (adversarial 44/0, track-a 25/0).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

AINative_OKR_CASAN5/.specify/scripts/bash/model-digest-check.sh

@@ -21,8 +21,9 @@ set -uo pipefail
 # Exit: 0 match/pinned/warned · 2 MISMATCH in block mode · 3 unpinned/undeterminable.
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "$SCRIPT_DIR/casan-paths.sh"
 PROJECT_ROOT="$(cd "$SCRIPT_DIR/../../.." && pwd)"
-PIN_FILE="${CASAN_MODEL_DIGEST_PIN:-$PROJECT_ROOT/.specify/security/model-digest.pin}"
+PIN_FILE="${CASAN_MODEL_DIGEST_PIN:-$CASAN_HARNESS_ROOT/security/model-digest.pin}"
 mkdir -p "$(dirname "$PIN_FILE")"
 CMD="${1:-verify}"
 MODEL="${2:-${CASAN_MODEL:-ornith:9b}}"