fix: RTC observed live with provenance, non-circular PIS/COFINS applicability, canonical CST normalization (1.1.8)

- RTC: Agent reads ALL PARAMETROS rows every sync (conflict => off), reports rtc_source/rtc_observed_at/rtc_param_rows; legal_effective_context is informational only
- PIS/COFINS: applicability from CRT + PISCOFINS flag + incidence only (never from empty fields); Simples w/o special treatment NOT_APPLICABLE, taxed regime with explicit N OPTIONAL, unreadable declaration NEEDS_REVIEW
- CST: one digit with an official zero-padded form is VALID_AFTER_NORMALIZATION (non-blocking warning), nothing is written to the ERP
- tests: RTC toggle 0->1->0 across syncs (Agent + Hub stale closing), non-circularity, normalization, panel provenance

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

docs/runs/unified_coverage_e2e_CONSTRUCAO.json

@@ -276,11 +276,26 @@
      ]
     }
    ],
+   "non_canonical_warnings": 0,
    "context": {
     "rtc_enabled": true,
+    "erp_rtc_enabled": true,
     "rtc_supported": true,
     "rtc_catalog_valid": true,
-    "rtc_param": 1,
+    "rtc_param": "1",
+    "rtc_source": "PARAMETROS.USAR_REFORMA_TRIBUTARIA",
+    "rtc_param_rows": 1,
+    "rtc_param_conflict": false,
+    "rtc_observed_at": "2026-09-24T20:40:41+00:00",
+    "legal_effective_context": {
+     "crt": "1",
+     "informational_only": true,
+     "ibs_cbs_in_documents": "FROM_2027_FOR_SIMPLES_ORIENTATION_PENDING",
+     "sources": [
+      "NT 2025.002-RTC v1.51 (Portal NF-e, 04/08/2026): CRT 1/2/4 orientations in a future NT; IBS/CBS taxation of these taxpayers only from 2027",
+      "LC 214/2025 art. 348"
+     ]
+    },
     "catalog_integrity": {
      "classes": 145,
      "cst": 18,
@@ -291,7 +306,15 @@
      "valid": true
     },
     "crt": "1",
-    "products_evaluated": 3712
+    "products_evaluated": 3712,
+    "pis_cofins_applicability": {
+     "NOT_APPLICABLE": 3712
+    },
+    "non_canonical_warnings": {
+     "products": 0,
+     "by_type": {},
+     "samples": []
+    }
    }
   },
   "RTC_OFF_SIMULATION": {
@@ -315,7 +338,8 @@
     "NOT_APPLICABLE": 3712
    },
    "changed_products": 0,
-   "examples": []
+   "examples": [],
+   "non_canonical_warnings": 0
   },
   "RTC_ON_SIMULATION": {
    "rtc_enabled": true,
@@ -581,7 +605,8 @@
       "CCLASSTRIB_MISSING"
      ]
     }
-   ]
+   ],
+   "non_canonical_warnings": 0
   }
  },
  "SAFETY": {