docs: add v0.8.7 changelog + README release notes

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -7,6 +7,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.8.7] - 2026-05-03
+
+### Fixed
+- **Selection across transcript cell types** — the selection-tightening from
+  v0.8.6 (#383) restricted copy/select to user and assistant message bodies
+  only, so text in system notes, thinking blocks, and tool output could not be
+  copied. v0.8.7 removes the body-start gate; the rendered transcript block is
+  fully selectable again.
+
 ## [0.8.6] - 2026-05-03
 
 ### Added

README.md

@@ -140,6 +140,19 @@ cargo install --path crates/tui --locked   # requires Rust 1.85+
 
 ---
 
+## What's new in v0.8.7
+
+Quick patch on top of v0.8.6 to unblock copy/select.
+
+### ✂️ Selection works across the whole transcript
+
+The selection-tightening from v0.8.6 restricted copy/select to user and
+assistant message bodies, which made it impossible to copy text out of
+system notes, thinking blocks, or tool output. v0.8.7 drops that gate so
+the rendered transcript block is selectable end-to-end again.
+
+Full changelog: [CHANGELOG.md](CHANGELOG.md).
+
 ## What's new in v0.8.6
 
 ### 📝 AGENTS.md bootstrap (`/init`)