Mantis Skills: Remove INFO severity rating.

Removed the "INFO" severity rating from the pipeline. It is no longer supported in:
- schema.json (severity enum)
- mantis-researcher/SKILL.md (findings template)
- mantis-report/SKILL.md (appendix filtering logic, now focusing only on LOW priority)

This simplifies the triage and aligns initial severity levels with the final calibrated priorities (which do not support INFO).

TAG=agy
CONV=8b947099-cf74-4472-a752-0d98e33667af

Change-Id: I29cbd519666d2a7278bb9c3778b4a517c2787684

Author: nickg-ca

mantis-report/SKILL.md

@@ -59,11 +59,11 @@ Execute the reporting stage as follows:
             include false positives, non-viable findings, findings that failed
             to reproduce, or ordinary statically confirmed findings that lack
             empirical execution traces.
-    -   **Severity Filtering:** Exclude findings with a priority of `"LOW"` or
-        `"INFO"` from the main report body. You must place these lower-priority
-        issues into a separate, dedicated "Appendix: Low and Info Severity
-        Findings" section at the very end of the report, keeping the main report
-        focused on high-risk issues.
+    -   **Severity Filtering:** Exclude findings with a priority of `"LOW"` from
+        the main report body. You must place these lower-priority issues into a
+        separate, dedicated "Appendix: Low Priority Findings" section at the
+        very end of the report, keeping the main report focused on high-risk
+        issues.
 
 2.  **Extract Key Artifacts:** For each reproduced finding, extract and format:
 

mantis-researcher/SKILL.md

@@ -125,7 +125,7 @@ Execute the research stage as follows:
   "title": "Authorization bypass or Memory bounds violation in [function_name]",
   "description": "Thorough root cause analysis detailing why the function is flawed under untrusted input.",
   "impact": "Exploit outcome (e.g., Privilege escalation, Memory corruption, Data exfiltration).",
-  "severity": "CRITICAL / HIGH / MEDIUM / LOW / INFO",
+  "severity": "CRITICAL / HIGH / MEDIUM / LOW",
   "privileges_required": "NONE / LOW / HIGH",
   "attacker_position": "EXTERNAL / INTERNAL_NETWORK / IN_CLUSTER / LOCAL / HOST_SYSTEM / SUPPLY_CHAIN / PHYSICAL_TEMPORARY / PHYSICAL_LONG_TERM",
   "user_interaction": "NONE / REQUIRED",

schema.json

@@ -53,7 +53,7 @@
         },
         "severity": {
           "type": "string",
-          "enum": ["CRITICAL", "HIGH", "MEDIUM", "LOW", "INFO"],
+          "enum": ["CRITICAL", "HIGH", "MEDIUM", "LOW"],
           "description": "Initial severity estimate."
         },
         "privileges_required": {