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/cost-spike-detect.sh

@@ -19,6 +19,7 @@ set -uo pipefail
 #       3 not enough data for the RELATIVE test and no absolute/cumulative cap set.
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "$SCRIPT_DIR/casan-paths.sh"
 PROJECT_ROOT="$(cd "$SCRIPT_DIR/../../.." && pwd)"
 # SEC-23 (MT-03): per-tenant cost/quota. With no explicit log arg, a tenant run
 # evaluates its OWN usage log so one tenant's spend never counts against another's
@@ -29,7 +30,7 @@ elif [[ -n "${CASAN_TENANT_ID:-}" ]]; then
   LOG="$(bash "$SCRIPT_DIR/tenant-store.sh" resolve telemetry/provider-usage.jsonl 2>/dev/null)" \
     || { echo "COST_SPIKE_TENANT_DENIED" >&2; exit 3; }
 else
-  LOG="$PROJECT_ROOT/.specify/logs/level5/provider-usage.jsonl"
+  LOG="$CASAN_STATE_ROOT/logs/level5/provider-usage.jsonl"
 fi
 MULT="${2:-3.0}"