docs: add limitations section, honest positioning, remove unsubstantiated claims

Author: mcandiri

README.md

@@ -1,6 +1,6 @@
 # LiveSQL
 
-> See how your SQL actually executes. Real-time query visualization with bottleneck detection, index recommendations, and animated execution flow.
+> Query plan visualization with bottleneck detection, index recommendations, and animated execution flow.
 
 [![.NET 8](https://img.shields.io/badge/.NET-8.0-512BD4?logo=dotnet)](https://dotnet.microsoft.com/)
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](LICENSE)
@@ -22,7 +22,7 @@ You write SQL. The database does... something. SSMS shows you a confusing execut
 LiveSQL makes it visual, animated, and understandable:
 
 - **See** data flow step by step through every operator
-- **Spot** table scans, expensive sorts, and bad estimates instantly
+- **Spot** table scans, expensive sorts, and bad estimates at a glance
 - **Fix** problems with ready-to-run index recommendations
 - **Compare** before/after plans side by side
 
@@ -71,6 +71,18 @@ Run a query, optimize it, run it again -- then compare both execution plans side
 
 ---
 
+## Limitations
+
+- **Read-only** — LiveSQL never modifies your database. It only retrieves execution plans.
+
+- **Estimated plans only** — for SQL Server, uses `SET STATISTICS XML ON` which requires the query to actually execute. For safe analysis of expensive queries, use estimated plans.
+
+- **No query result display** — this is a plan visualizer, not a query runner.
+
+- **Demo mode uses synthetic data** — the 6 example plans are handcrafted to demonstrate common patterns, not captured from a real database.
+
+---
+
 ## Architecture
 
 ```
@@ -162,15 +174,15 @@ Tests cover XML/JSON plan parsing, bottleneck detection rules, index recommendat
 
 ---
 
-## Born From Production
+## Why This Exists
 
-> LiveSQL was built from years of performance tuning SQL queries powering enterprise platforms with millions of rows. The patterns it detects -- missing indexes, estimate skew, unnecessary sorts -- are the same ones that cause real outages and slow dashboards in production systems.
+> Built after spending too many hours squinting at SSMS execution plan icons and scrolling through EXPLAIN ANALYZE walls of text. The bottleneck detection rules come from real performance incidents — queries that looked fine until they hit 10M+ row tables and ground dashboards to a halt.
 
 ---
 
 ## Security
 
-LiveSQL is designed to be **read-only** and safe to point at production databases:
+LiveSQL is designed to be **read-only**:
 
 - **Read-only by design.** Uses `SET STATISTICS XML ON` / `EXPLAIN (ANALYZE, FORMAT JSON)` only -- never modifies data or schema
 - **Connection strings are never logged.** The connector layer treats connection strings as opaque secrets