release: 0.6.6

The live-edge catch-up (8c4f4a0, b4a4c00) landed after the v0.6.5 tag, so
the 0.6.5 artifacts do not contain it — the same gap that left the fix out
of v0.6.4. Cut 0.6.6 so the published build actually carries it.

Local-only changes (no wire change; PROTO planes unchanged), so this is a
PATCH bump per VERSIONING.md.

601 lib tests green, clippy clean.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

CHANGELOG.md

@@ -4,6 +4,8 @@ All notable changes to PeerSpeak are documented here.
 
 ## [Unreleased]
 
+## [0.6.6] — 2026-07-19
+
 ### Fixed
 - **A screen share that falls behind now catches back up.** On a lossy
   connection (satellite links are the worst case) the share could settle several
@@ -14,6 +16,15 @@ All notable changes to PeerSpeak are documented here.
   help. Applies to the Low latency setting; Smooth intentionally keeps its
   larger buffer.
 
+### Changed
+- **Low latency now keeps a tighter viewer buffer.** The screen-share cache
+  setting is a size in megabytes, which at a given bitrate quietly decides how
+  many *seconds* behind a viewer can drift — a 2 MB buffer turned out to hold
+  about six seconds of a typical share. Low latency now caps that buffer at 1 MB
+  regardless of the setting, which halved how far behind a share fell on a bad
+  connection before anything else kicked in. Smooth still honors the value you
+  choose, since a deep buffer is the point of that mode.
+
 ## [0.6.5] — 2026-07-19
 
 ### Added