[WIP] [Security] Comprehensive Data Sanitization and Input Validation Audit

IMPLEMENTATION_NOTES.md

@@ -0,0 +1,17 @@
+# Implementation Notes — Issue #164
+
+**Issue:** [Security] Comprehensive Data Sanitization and Input Validation Audit
+**Upstream:** https://github.com/BETAIL-BOYS/TradeFlow-API/issues/164
+
+## Acceptance Criteria
+
+**Description:** Several administrative and public search endpoints parse user input strings directly into database query contexts, posing potential injection risks and Cross-Site Scripting (XSS) vectors if returned directly to frontend clients.
+**Context / Motivation:** Tightly validation-checking all inputs at the API boundaries guarantees that malformed inputs are blocked long before they hit internal application execution engines.
+**Acceptance Criteria:**
+- [ ] Integrate a schema validation layer (like Zod or Joi) across all incoming payload points (`req.body`, `req.query`, `req.params`).
+- [ ] Ensure any text search parameters escape special SQL/NoSQL parameters explicitly.
+- [ ] Clean and sanitize any user-provided metadata using an XSS filter before saving it to the database.
+**Technical Pointers:** Rely entirely on parameterized queries or ORM safe-execution paradigms instead of constructing query components via raw string concatenation.
+
+---
+_Delete this file before merging._