Add post-generation QC API linter with 8 lint rules

Static linter (regex+AST hybrid) catches and auto-fixes common LLM mistakes
before code hits QC compilation: PascalCase methods/attrs/defs, wrong
Resolution casing, Action() wrappers, len() on RollingWindow, .Values on
RollingWindow. Warns on History DataFrame misuse, history() in on_data(),
and indicator name shadowing. Integrated at Phase 1.5 in processor pipeline,
after regeneration in fidelity loop, and in ValidateCodeTool.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: SL-Mar

quantcoder/core/__init__.py

@@ -1,7 +1,7 @@
 """Core modules for QuantCoder."""
 
 # Lazy imports to avoid loading heavy dependencies at import time
-__all__ = ["ArticleProcessor", "LLMHandler", "SummaryStore"]
+__all__ = ["ArticleProcessor", "LLMHandler", "SummaryStore", "lint_qc_code", "LintResult"]
 
 
 def __getattr__(name):
@@ -14,4 +14,10 @@ def __getattr__(name):
     if name == "SummaryStore":
         from .summary_store import SummaryStore
         return SummaryStore
+    if name == "lint_qc_code":
+        from .qc_linter import lint_qc_code
+        return lint_qc_code
+    if name == "LintResult":
+        from .qc_linter import LintResult
+        return LintResult
     raise AttributeError(f"module {__name__!r} has no attribute {name!r}")

quantcoder/core/processor.py

@@ -580,6 +580,19 @@ def generate_code_from_summary(self, summary_text: str) -> Optional[str]:
         else:
             self.logger.info("No stubs detected — skipping Stage 2")
 
+        # -- Phase 1.5: QC API linting ----------------------------------------
+        from .qc_linter import lint_qc_code
+
+        lint_result = lint_qc_code(qc_code)
+        if lint_result.had_fixes and self._validate_code(lint_result.code):
+            self.logger.info(
+                "QC linter applied %d auto-fixes",
+                sum(1 for i in lint_result.issues if i.fixed),
+            )
+            qc_code = lint_result.code
+        for hint in lint_result.unfixable_hints:
+            self.logger.warning("QC linter warning: %s", hint)
+
         # -- Phase 2: fidelity assessment loop (unchanged) --------------------
         for fidelity_attempt in range(self.max_fidelity_attempts):
             self.logger.info(f"Fidelity assessment attempt {fidelity_attempt + 1}")
@@ -619,6 +632,10 @@ def generate_code_from_summary(self, summary_text: str) -> Optional[str]:
                 syntax_attempt += 1
 
             if self._validate_code(new_code):
+                # Lint regenerated code too
+                regen_lint = lint_qc_code(new_code)
+                if regen_lint.had_fixes and self._validate_code(regen_lint.code):
+                    new_code = regen_lint.code
                 qc_code = new_code
             else:
                 self.logger.warning("Regenerated code failed syntax validation, keeping previous version")