diff --git a/crates/tinyclient/src/gui/components/overlay.rs b/crates/tinyclient/src/gui/components/overlay.rs
index 9fbc7ec..7225a94 100644
--- a/crates/tinyclient/src/gui/components/overlay.rs
+++ b/crates/tinyclient/src/gui/components/overlay.rs
@@ -30,8 +30,8 @@ impl Render for Tip {
             .font_family(theme::FONT)
             .type_small()
             .text_color(theme::text())
-            .child(self.words.clone())
-            .children(self.shortcut.clone().map(|keys| div().text_color(theme::text_faint()).child(keys)))
+            .child(div().flex_1().min_w_0().whitespace_normal().overflow_hidden().child(self.words.clone()))
+            .children(self.shortcut.clone().map(|keys| div().flex_none().whitespace_nowrap().text_color(theme::text_faint()).child(keys)))
     }
 }
 
diff --git a/crates/tinyclient/src/gui/conversation/images.rs b/crates/tinyclient/src/gui/conversation/images.rs
index a319bec..ed32737 100644
--- a/crates/tinyclient/src/gui/conversation/images.rs
+++ b/crates/tinyclient/src/gui/conversation/images.rs
@@ -139,9 +139,10 @@ pub fn decode(path: &Path, edge: u32, crop: Option<f32>) -> Option<Decoded> {
 
 #[cfg(not(target_os = "macos"))]
 fn decode_portable(path: &Path, edge: u32, crop: Option<f32>) -> Option<Decoded> {
-    let edge = edge.clamp(1, 8192);
-    let mut img = image::open(path).ok()?.into_rgba8();
+    let mut img = image::ImageReader::open(path).ok()?.with_guessed_format().ok()?.decode().ok()?.into_rgba8();
     let (w, h) = (img.width(), img.height());
+    // Cache paths have no suffix, and a requested thumbnail must not enlarge a small source.
+    let edge = edge.clamp(1, 8192).min(w.max(h));
     let (nw, nh) = if w >= h {
         let nh = ((h as u64 * edge as u64) / w as u64).max(1) as u32;
         (edge, nh)
@@ -693,6 +694,18 @@ mod tests {
         Path::new(env!("CARGO_MANIFEST_DIR")).join("tests/fixtures").join(name)
     }
 
+    #[test]
+    fn cached_images_decode_without_filename_extensions() {
+        for (ix, format) in [image::ImageFormat::Png, image::ImageFormat::Jpeg, image::ImageFormat::WebP].into_iter().enumerate() {
+            let path = std::env::temp_dir().join(format!("tc-extensionless-{}-{ix}", std::process::id()));
+            let image = image::RgbImage::from_pixel(32, 16, image::Rgb([220, 40, 60]));
+            image.save_with_format(&path, format).unwrap();
+            let decoded = decode(&path, 16, None).expect("cache files have no extension; use their bytes");
+            assert_eq!((decoded.width, decoded.height), (16, 8));
+            std::fs::remove_file(path).unwrap();
+        }
+    }
+
     #[test]
     fn a_moving_picture_is_read_for_frames_only_when_they_are_wanted() {
         // Only these are read whole: a GIF, a WebP marked animated, a PNG with an animation chunk.
diff --git a/docs/design/polish/01-system.md b/docs/design/polish/01-system.md
index 8636479..f59d553 100644
--- a/docs/design/polish/01-system.md
+++ b/docs/design/polish/01-system.md
@@ -178,6 +178,8 @@ Items that do not apply are disabled, never hidden; names follow the open place
 - **Animates, only**: menu and popover in 120 / out 80 (opacity + 4 toward anchor); modal and toast in 160 / out 100
   (opacity + 8 rise); scrollbar fade 150 after 800 idle; typing dots stepped at 400. Reduce Motion: all 0. Nothing else.
 - **Tooltips**: 500 delay, appear whole, 0 delay for 1.5 s after one closes, gone on mouse-down or leave. Every
-  icon-only button has one, with its shortcut in `text_faint`.
+  icon-only button has one, with its shortcut in `text_faint`. Text wraps within
+  the 240-point tooltip; the shortcut stays on one line beside it. Long failure
+  reasons must not paint outside the tooltip background.
 - **Focus**, keyboard only: rows and menu items a 2 inset `focus` ring over any fill; controls a 2 gap then a 2 ring;
   fields a `focus` border + 3 halo while focused. The list cursor is the ring, the open conversation the fill (`07` R8).
diff --git a/docs/design/polish/06-composer.md b/docs/design/polish/06-composer.md
index d0a8c0f..a73bd3f 100644
--- a/docs/design/polish/06-composer.md
+++ b/docs/design/polish/06-composer.md
@@ -182,6 +182,9 @@ removing a file (Discord) and replacing a photo (Telegram) are P2.
   are computed from the trigger bounds before layout. Grid = `uniform_list` of rows (9 emoji / 1 justified GIF row / 4
   stickers), so ~12 rows exist; images decode in `Images` only for visible rows and drop on scroll-off; the entity and
   `media/<net>/pick/` die on close.
+- **Still-image decode**: media cache filenames have no extension. On Linux and
+  Windows, detect the image format from its bytes, as on macOS. Thumbnail decoding
+  shrinks large sources but never enlarges a smaller source to the requested edge.
 - **GIF decode rule**: every cell is a first-frame still (`images.rs` reads index 0 only). The one hovered cell swaps to
   `img()` of the provider's smallest GIF rendition (Tenor `tinygif`, ~220 px): this rev's `img()` steps frames itself
   and stops under `reduce_motion()`. Played only if width × height × 4 × frames ≤ 8 MB, else it stays still; dropped