chore(entropy): Phase 5 start - fix duplicate line bug and document findings

- Fix duplicate line bug in rag_emb_provider.setter (app_controller.py)
- Add entropy_findings.md documenting audit results
- Update plan.md with Phase 5 tasks and findings
- Note: Property getter/setter 'duplicates' are false positives - proper Python patterns

.slop_cache/summary_cache.json

@@ -86,5 +86,13 @@
  "C:\\Users\\Ed\\AppData\\Local\\Temp\\pytest-of-Ed\\pytest-846\\test_force_full0\\other.txt": {
   "hash": "04d61c0832f9cbc2a210334352425d2519890a0a5945da96ccc5bd9ff101c4d3",
   "summary": "This document is a simple text file containing ten lines of content, with the first eight lines previewed. Its purpose appears to be for basic data storage or as a placeholder.\n\n**Outline:**\n**TXT** \u2014 10 lines\npreview:\n```\nline1\nline2\nline3\nline4\nline5\nline6\nline7\nline8\n```"
+ },
+ "C:\\Users\\Ed\\AppData\\Local\\Temp\\pytest-of-Ed\\pytest-847\\test_auto_aggregate_skip0\\file1.txt": {
+  "hash": "d0b425e00e15a0d36b9b361f02bab63563aed6cb4665083905386c55d5b679fa",
+  "summary": "This document contains a single line of text, \"content1\". Its purpose and key takeaways are limited to this singular piece of content.\n\n**Outline:**\n**TXT** \u2014 1 lines\npreview:\n```\ncontent1\n```"
+ },
+ "C:\\Users\\Ed\\AppData\\Local\\Temp\\pytest-of-Ed\\pytest-847\\test_force_full0\\other.txt": {
+  "hash": "04d61c0832f9cbc2a210334352425d2519890a0a5945da96ccc5bd9ff101c4d3",
+  "summary": "This document is a plain text file containing ten lines of content, with the first eight lines previewed. Its purpose appears to be simply to hold and present this sequential text.\n\n**Outline:**\n**TXT** \u2014 10 lines\npreview:\n```\nline1\nline2\nline3\nline4\nline5\nline6\nline7\nline8\n```"
  }
 }