docs: update all documentation to reflect v3.0 functionality

Update README, CLI reference, and developer guide to cover delimiter
selector, inline checkboxes/dropdowns, live surviving rows preview,
multi-row survivors, and apply_review_decisions(). Remove dead link.

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

README.md

@@ -1,6 +1,6 @@
 # DataTools Deduplicator
 
-Find and remove duplicate rows in CSV and Excel files — with fuzzy matching, smart normalization, and interactive review.
+Find and remove duplicate rows in CSV, delimited text, and Excel files — with fuzzy matching, smart normalization, and interactive review.
 
 ## Features
 
@@ -9,7 +9,7 @@ Find and remove duplicate rows in CSV and Excel files — with fuzzy matching, s
 - **5 built-in normalizers** — email (Gmail dot/plus), phone (E.164), name (titles/suffixes), address (USPS), string (whitespace/case)
 - **Merge mode** — fill missing fields in the surviving row from removed duplicates
 - **4 survivor rules** — keep first, last, most complete, or most recent row per group
-- **Interactive review** — inspect each match group and decide: merge, keep both, or skip
+- **Interactive review** — inspect match groups with inline checkboxes and column dropdowns, cherry-pick values, preview surviving rows live
 - **Config profiles** — save and reload your settings as JSON for repeatable runs
 - **Dual interface** — full CLI for automation, Streamlit GUI for visual review
 - **Dry-run by default** — preview what would change before writing anything
@@ -111,7 +111,6 @@ When `--apply` is used, three files are produced:
 
 - [CLI Reference](docs/CLI-REFERENCE.md) — every flag with examples and recipe sections
 - [Developer Guide](docs/DEVELOPER.md) — architecture, data flow, how to extend
-- [User Guide](docs/USER-GUIDE.md) — installation and usage for end users
 
 ## Requirements