update docs

Author: kan-bayashi

CLAUDE.md

@@ -52,13 +52,15 @@ cargo clippy         # Lint
 ## Environment Variables
 
 - `SIVIT_NAV_LATCH_MS` - Navigation latch (ms) before drawing images (default: 150)
-- `SIVIT_RENDER_CACHE_SIZE` - Client-side render cache size (encoded images in memory, default: 15)
-- `SIVIT_TMUX_KITTY_MAX_PIXELS` - Max pixels for tmux+kitty in `Normal` mode (default: 1500000)
+- `SIVIT_RENDER_CACHE_SIZE` - Client-side render cache size (encoded images in memory, default: 100)
+- `SIVIT_TMUX_KITTY_MAX_PIXELS` - Max pixels for tmux+kitty in `Normal` mode (default: 2000000)
 - `SIVIT_FORCE_ALT_SCREEN` - Force alternate screen mode
 - `SIVIT_NO_ALT_SCREEN` - Disable alternate screen mode
 - `SIVIT_DEBUG` - Enable debug info in status bar
 - `SIVIT_TRACE_WORKER` - Write worker timing logs to `/tmp/sivit_worker.log`
 - `SIVIT_KGP_NO_COMPRESS` - Disable zlib compression for KGP transmission
+- `SIVIT_COMPRESS_LEVEL` - Zlib compression level 0-9 (default: 6, higher = smaller but slower)
+- `SIVIT_PREFETCH_COUNT` - Number of images to prefetch ahead/behind (default: 5)
 
 ## Coding Conventions
 

README.md

@@ -10,6 +10,8 @@ A terminal-based image viewer with sxiv-like keybindings. Works over SSH with Tm
 
 - Kitty Graphics Protocol (KGP) image rendering
 - sxiv/vim-like keyboard navigation (counts supported)
+- Zlib compression for fast image transmission
+- Prefetch adjacent images for instant navigation
 - Render cache for snappy navigation
 - `Fit` toggle (upscale to viewport) + `Normal` (shrink-only)
 
@@ -23,6 +25,22 @@ Tested: Ghostty + tmux.
 
 ## Installation
 
+### From Release
+
+Download the latest binary from [Releases](https://github.com/kan-bayashi/sivit/releases):
+
+```bash
+# macOS (Apple Silicon)
+curl -L https://github.com/kan-bayashi/sivit/releases/latest/download/sivit-aarch64-apple-darwin.tar.gz | tar xz
+sudo mv sivit /usr/local/bin/
+
+# Linux (x86_64)
+curl -L https://github.com/kan-bayashi/sivit/releases/latest/download/sivit-x86_64-unknown-linux-gnu.tar.gz | tar xz
+sudo mv sivit /usr/local/bin/
+```
+
+### From Source
+
 ```bash
 cargo install --path .
 ```
@@ -54,9 +72,12 @@ Vim-like counts are supported (e.g. `5j`, `10G`).
 
 | Env | Default | Description |
 |-----|---------|-------------|
-| `SIVIT_NAV_LATCH_MS` | `150` | Navigation latch (ms) before drawing images; helps rapid key taps feel snappy |
-| `SIVIT_RENDER_CACHE_SIZE` | `15` | Render cache entries (can be memory-heavy) |
-| `SIVIT_TMUX_KITTY_MAX_PIXELS` | `1500000` | Max pixels in `Normal` mode (tmux+kitty compatibility); ignored in `Fit` mode |
+| `SIVIT_NAV_LATCH_MS` | `150` | Navigation latch (ms) before drawing images |
+| `SIVIT_RENDER_CACHE_SIZE` | `100` | Render cache entries |
+| `SIVIT_PREFETCH_COUNT` | `5` | Number of images to prefetch ahead/behind |
+| `SIVIT_COMPRESS_LEVEL` | `6` | Zlib compression level 0-9 |
+| `SIVIT_KGP_NO_COMPRESS` | unset | Disable zlib compression |
+| `SIVIT_TMUX_KITTY_MAX_PIXELS` | `2000000` | Max pixels in `Normal` mode (tmux+kitty) |
 | `SIVIT_FORCE_ALT_SCREEN` | unset | Force alternate screen |
 | `SIVIT_NO_ALT_SCREEN` | unset | Disable alternate screen |