feat: implement full-stack opportunity screener with Python schemas, Angular UI…

feat: implement full-stack opportunity screener with Python schemas, Angular UI components, and data repository.

dohasecuritiesstockai/opportunity_screener/repository.py

+"""Token-safe filesystem persistence for opportunity scans."""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+from .schema import OpportunityScanResult
+
+
+class OpportunityRepository:
+    def __init__(self, results_dir: str | Path) -> None:
+        self.directory = Path(results_dir) / "api" / "opportunities"
+        self.directory.mkdir(parents=True, exist_ok=True)
+
+    def save(
+        self,
+        result: OpportunityScanResult,
+        output_path: str | Path | None = None,
+    ) -> Path:
+        path = Path(output_path) if output_path else self.directory / f"{result.scan_id}.json"
+        path.parent.mkdir(parents=True, exist_ok=True)
+        path.write_text(result.model_dump_json(indent=2), encoding="utf-8")
+        return path
+
+    def get(self, scan_id: str) -> OpportunityScanResult | None:
+        if not scan_id or Path(scan_id).name != scan_id:
+            return None
+        path = self.directory / f"{scan_id}.json"
+        if not path.is_file():
+            return None
+        return OpportunityScanResult.model_validate_json(path.read_text(encoding="utf-8"))
+
+    def latest(self) -> OpportunityScanResult | None:
+        paths = sorted(
+            self.directory.glob("*.json"),
+            key=lambda path: path.stat().st_mtime,
+            reverse=True,
+        )
+        return self.get(paths[0].stem) if paths else None