diff --git a/frontend/CLAUDE.md b/frontend/CLAUDE.md
index dc19ee4a..352a983e 100644
--- a/frontend/CLAUDE.md
+++ b/frontend/CLAUDE.md
@@ -50,6 +50,8 @@ This app ships to non-developers. Anything a user sees has to read like a person
 - **Friendly without being cute.** Conversational, not chirpy. "Want me to shrink it down to a summary?" not "Whoops! That file is huge!".
 - **Minimalist by default. Less is more.** One short message, one subtle animation, one verb. Do NOT add rotating progress messages, multi-line status text, percentage counters, or step-by-step explainers unless the user explicitly needs them. A pulsing dot + "Shrinking" beats a 4-message carousel + spinner + progress bar every time. The user knows what they clicked; we just need to confirm we're alive.
 - **Animations are subtle.** Pulse, fade, soft scale (≤1.0× to 0.6×). No bounce, no flashing, no harsh blinking, no rotating spinners with multiple emoji. Easing: `ease-in-out`. Duration: 1-1.5s for ambient states (loading), 150-250ms for state changes (hover, mode flip).
+- **Don't expose absolute filesystem paths to users.** Tooltips, file chips, and labels should show only the file's basename (e.g. `llama2.pdf`), never the temp-dir path (`/var/folders/s7/.../self-swarm-uploads/llama2.pdf`). Users don't care where their file landed in temp, and a 200-char tooltip dangling over the chat input is ugly. If the user genuinely needs the path, expose it via a "copy path" action, not a hover tooltip.
+- **State changes from one button must invalidate downstream estimates.** If a button claims to shrink/clear/reset something the next user action depends on, you have to invalidate the cached estimate too. Example: clicking "Compact memory" calls `/compact` server-side, but the renderer's `tokens.input` was a snapshot from the previous round-trip — leaving it stale makes the next send re-fire the same "over context window" banner, looking like the button did nothing. Always pair an action with the redux update that its UX promise implies.
 
 ## Pitfalls
 
diff --git a/frontend/src/app/pages/AgentChat/ChatInput/view/AttachmentChips.tsx b/frontend/src/app/pages/AgentChat/ChatInput/view/AttachmentChips.tsx
index 695c9e0b..f0aae287 100644
--- a/frontend/src/app/pages/AgentChat/ChatInput/view/AttachmentChips.tsx
+++ b/frontend/src/app/pages/AgentChat/ChatInput/view/AttachmentChips.tsx
@@ -112,7 +112,7 @@ export const AttachmentChips: React.FC<Props> = ({
             return (
               <Tooltip
                 key={`${cp.path}-${idx}`}
-                title={copiedPathIdx === idx ? 'Copied!' : cp.path}
+                title={copiedPathIdx === idx ? 'Copied!' : (cp.path.split('/').pop() || cp.path)}
                 arrow
                 placement="top"
                 slotProps={{
@@ -120,7 +120,7 @@ export const AttachmentChips: React.FC<Props> = ({
                     sx: {
                       fontFamily: c.font.mono,
                       fontSize: '0.7rem',
-                      maxWidth: 420,
+                      maxWidth: 280,
                       wordBreak: 'break-all',
                     },
                   },
diff --git a/frontend/src/app/pages/AgentChat/ChatInput/view/SendBlockBanner.tsx b/frontend/src/app/pages/AgentChat/ChatInput/view/SendBlockBanner.tsx
index ef82bf25..0fe04351 100644
--- a/frontend/src/app/pages/AgentChat/ChatInput/view/SendBlockBanner.tsx
+++ b/frontend/src/app/pages/AgentChat/ChatInput/view/SendBlockBanner.tsx
@@ -16,17 +16,18 @@ interface Props {
 }
 
 export const SendBlockBanner: React.FC<Props> = ({ sendBlock, c, sessionId, setSendBlock, setContextPaths, setModelAnchor }) => {
-  const fmt = (n: number) => n >= 1000 ? `${(n / 1000).toFixed(1)}K` : String(n);
-  const over = sendBlock.estimate - sendBlock.window;
+  const fmt = (n: number) => n >= 1000 ? `${(n / 1000).toFixed(0)}K` : String(n);
   return (
-    <Box sx={{ mx: 1.5, mt: 1, mb: 0.5, p: 1.25, borderRadius: '10px', border: `1px solid ${c.status.error}`, bgcolor: `${c.status.error}10` }}>
-      <Typography sx={{ fontSize: '0.78rem', fontWeight: 600, color: c.status.error, mb: 0.5 }}>
-        This send would overflow the model's context window
+    <Box sx={{
+      mx: 1.5, mt: 1, mb: 0.5, px: 2, py: 1.5,
+      borderRadius: '12px',
+      bgcolor: c.bg.surface,
+      border: `1px solid ${c.border.medium}`,
+    }}>
+      <Typography sx={{ fontSize: '0.9rem', color: c.text.primary, lineHeight: 1.5, mb: 1 }}>
+        That's a lot to send at once. Pick one:
       </Typography>
-      <Typography sx={{ fontSize: '0.72rem', color: c.text.secondary, mb: 0.75, fontVariantNumeric: 'tabular-nums' }}>
-        ~{fmt(sendBlock.estimate)} of {fmt(sendBlock.window)} tokens ({over > 0 ? `${fmt(over)} over` : 'at cap'}). History {fmt(sendBlock.history)} · Files {fmt(sendBlock.files)} · Tools/MCPs {fmt(sendBlock.framework)} · This message {fmt(sendBlock.prompt)}.
-      </Typography>
-      <Box sx={{ display: 'flex', gap: 0.5, flexWrap: 'wrap' }}>
+      <Box sx={{ display: 'flex', gap: 0.75, flexWrap: 'wrap' }}>
         {sessionId && (
           <Box
             component="button"
@@ -40,11 +41,13 @@ export const SendBlockBanner: React.FC<Props> = ({ sendBlock, c, sessionId, setS
               } catch (err) { console.error(err); }
             }}
             sx={{
-              background: c.accent.primary, color: '#fff', border: 'none', borderRadius: '6px',
-              px: 1, py: 0.5, fontSize: '0.72rem', cursor: 'pointer', '&:hover': { opacity: 0.9 },
+              bgcolor: c.accent.primary, color: '#fff', border: 'none', borderRadius: '6px',
+              px: 1.5, py: 0.7, fontSize: '0.82rem', fontWeight: 500, cursor: 'pointer',
+              transition: 'background 0.15s ease',
+              '&:hover': { bgcolor: c.accent.hover },
             }}
           >
-            Compact memory
+            Shrink history
           </Box>
         )}
         {sendBlock.largestFile && (
@@ -56,21 +59,25 @@ export const SendBlockBanner: React.FC<Props> = ({ sendBlock, c, sessionId, setS
               setSendBlock(null);
             }}
             sx={{
-              background: 'transparent', color: c.text.primary, border: `1px solid ${c.border.subtle}`,
-              borderRadius: '6px', px: 1, py: 0.5, fontSize: '0.72rem', cursor: 'pointer',
-              '&:hover': { background: c.bg.secondary },
+              bgcolor: 'transparent', color: c.text.secondary,
+              border: `1px solid ${c.border.medium}`, borderRadius: '6px',
+              px: 1.5, py: 0.7, fontSize: '0.82rem', cursor: 'pointer',
+              transition: 'background 0.15s ease, color 0.15s ease',
+              '&:hover': { bgcolor: c.bg.secondary, color: c.text.primary },
             }}
           >
-            Detach largest file (~{fmt(sendBlock.largestFile.tokens)})
+            Remove biggest file
           </Box>
         )}
         <Box
           component="button"
           onClick={(e) => { setModelAnchor(e.currentTarget as HTMLElement); setSendBlock(null); }}
           sx={{
-            background: 'transparent', color: c.text.primary, border: `1px solid ${c.border.subtle}`,
-            borderRadius: '6px', px: 1, py: 0.5, fontSize: '0.72rem', cursor: 'pointer',
-            '&:hover': { background: c.bg.secondary },
+            bgcolor: 'transparent', color: c.text.secondary,
+            border: `1px solid ${c.border.medium}`, borderRadius: '6px',
+            px: 1.5, py: 0.7, fontSize: '0.82rem', cursor: 'pointer',
+            transition: 'background 0.15s ease, color 0.15s ease',
+            '&:hover': { bgcolor: c.bg.secondary, color: c.text.primary },
           }}
         >
           Switch model
@@ -79,9 +86,10 @@ export const SendBlockBanner: React.FC<Props> = ({ sendBlock, c, sessionId, setS
           component="button"
           onClick={() => setSendBlock(null)}
           sx={{
-            background: 'transparent', color: c.text.muted, border: 'none',
-            borderRadius: '6px', px: 1, py: 0.5, fontSize: '0.72rem', cursor: 'pointer',
-            '&:hover': { background: c.bg.secondary },
+            bgcolor: 'transparent', color: c.text.muted, border: 'none',
+            borderRadius: '6px', px: 1.5, py: 0.7, fontSize: '0.82rem', cursor: 'pointer',
+            transition: 'color 0.15s ease',
+            '&:hover': { color: c.text.secondary },
           }}
         >
           Dismiss
diff --git a/frontend/src/shared/state/agentsSlice.ts b/frontend/src/shared/state/agentsSlice.ts
index 40b29305..5f104dcf 100644
--- a/frontend/src/shared/state/agentsSlice.ts
+++ b/frontend/src/shared/state/agentsSlice.ts
@@ -744,6 +744,14 @@ const agentsSlice = createSlice({
       const session = state.sessions[action.payload.sessionId];
       if (!session) return;
       session.compacted_through_msg_id = action.payload.throughMsgId;
+      // The next preflight check looks at tokens.input to estimate "history used".
+      // After a compaction the real number is unknown until the next turn round-trips,
+      // but the OLD number is definitely wrong (it counts messages we just dropped).
+      // Zero it so preflight falls back to the char/4 estimate of remaining content,
+      // which is closer than holding the stale pre-compact value.
+      if (action.payload.throughMsgId) {
+        session.tokens = { input: 0, output: session.tokens?.output ?? 0 };
+      }
     },
 
     // Aux-LLM turn label; pill renderer prefers this over the static "Thinking..." verb.