diff --git a/packages/k8s-ui/package.json b/packages/k8s-ui/package.json
index 18cdad4a0..563dc9aac 100644
--- a/packages/k8s-ui/package.json
+++ b/packages/k8s-ui/package.json
@@ -72,6 +72,7 @@
     "lucide-react": ">=0.400.0",
     "react": ">=18.0.0",
     "react-dom": ">=18.0.0",
+    "tailwind-merge": ">=2",
     "yaml": ">=2.0.0"
   },
   "devDependencies": {
@@ -88,6 +89,7 @@
     "lucide-react": "^1.12.0",
     "react": "^19.2.4",
     "react-dom": "^19.2.4",
+    "tailwind-merge": "^3.5.0",
     "typescript": "^6.0.2",
     "vitest": "^4.1.5",
     "yaml": "^2.8.3"
diff --git a/packages/k8s-ui/src/components/ui/Tooltip.test.tsx b/packages/k8s-ui/src/components/ui/Tooltip.test.tsx
new file mode 100644
index 000000000..0f48069e2
--- /dev/null
+++ b/packages/k8s-ui/src/components/ui/Tooltip.test.tsx
@@ -0,0 +1,46 @@
+import { describe, it, expect } from 'vitest'
+import { renderToString } from 'react-dom/server'
+import { Tooltip } from './Tooltip'
+
+// Pins the wrapper-className merge contract: a caller passing
+// `wrapperClassName="block"` MUST override the default `inline-flex`
+// on the trigger span. Without `twMerge`, plain `clsx` concatenation
+// emits both `inline-flex` and `block`, and stylesheet ordering picks
+// the wrong one — breaks ChartBrowser's truncation flow because the
+// wrapper stays `inline-flex` and the child `truncate` never engages.
+describe('Tooltip wrapper className', () => {
+  it('lets the caller override the default display utility via twMerge', () => {
+    const html = renderToString(
+      <Tooltip content="hi" wrapperClassName="block">
+        <span>child</span>
+      </Tooltip>,
+    )
+    // Caller wins on the display group — twMerge drops the conflicting
+    // default. Assert each class independently; emit order is a
+    // twMerge implementation detail and varies across versions.
+    expect(html).toContain('block')
+    expect(html).toContain('max-w-full')
+    expect(html).not.toContain('inline-flex')
+  })
+
+  it('keeps the default display utility when no caller override is supplied', () => {
+    const html = renderToString(
+      <Tooltip content="hi">
+        <span>child</span>
+      </Tooltip>,
+    )
+    expect(html).toContain('inline-flex max-w-full')
+  })
+
+  it('merges arbitrary non-conflicting utilities from the caller alongside the defaults', () => {
+    const html = renderToString(
+      <Tooltip content="hi" wrapperClassName="min-w-0 flex-1">
+        <span>child</span>
+      </Tooltip>,
+    )
+    expect(html).toContain('inline-flex')
+    expect(html).toContain('max-w-full')
+    expect(html).toContain('min-w-0')
+    expect(html).toContain('flex-1')
+  })
+})
diff --git a/packages/k8s-ui/src/components/ui/Tooltip.tsx b/packages/k8s-ui/src/components/ui/Tooltip.tsx
index d55bcaf5e..8aef7b5ab 100644
--- a/packages/k8s-ui/src/components/ui/Tooltip.tsx
+++ b/packages/k8s-ui/src/components/ui/Tooltip.tsx
@@ -1,6 +1,7 @@
 import { ReactNode, useState, useRef, useEffect, useCallback } from 'react'
 import { createPortal } from 'react-dom'
 import { clsx } from 'clsx'
+import { twMerge } from 'tailwind-merge'
 import { computeTooltipPosition } from './tooltip-position'
 
 // Module-level singleton coordinator: only one Tooltip can be visible
@@ -199,7 +200,14 @@ export function Tooltip({
     <>
       <span
         ref={triggerRef}
-        className={clsx('inline-flex max-w-full', wrapperClassName)}
+        // twMerge so a caller-supplied display utility (e.g.
+        // `wrapperClassName="block"` from ChartBrowser, where the
+        // wrapper needs to fill its `flex-1 min-w-0` parent so the
+        // child's `truncate` triggers) actually overrides our default
+        // `inline-flex`. Plain clsx concatenation can't override
+        // utilities that share a Tailwind property group, since the
+        // generated stylesheet ordering — not className order — wins.
+        className={twMerge(clsx('inline-flex max-w-full', wrapperClassName))}
         style={wrapperStyle}
         onMouseEnter={showTooltip}
         onMouseLeave={hideTooltip}
diff --git a/packages/k8s-ui/src/utils/index.ts b/packages/k8s-ui/src/utils/index.ts
index a235d775a..9c82c0e69 100644
--- a/packages/k8s-ui/src/utils/index.ts
+++ b/packages/k8s-ui/src/utils/index.ts
@@ -14,3 +14,4 @@ export * from './k8s-errors'
 export * from './parse-go-time'
 export * from './view-transition'
 export * from './validators'
+export * from './user-initials'
diff --git a/packages/k8s-ui/src/utils/user-initials.test.ts b/packages/k8s-ui/src/utils/user-initials.test.ts
new file mode 100644
index 000000000..9f37f3c3a
--- /dev/null
+++ b/packages/k8s-ui/src/utils/user-initials.test.ts
@@ -0,0 +1,95 @@
+import { describe, it, expect } from 'vitest'
+import { computeUserInitials } from './user-initials'
+
+// Pin the contract that the avatar circle never tries to render a
+// non-letter glyph: previous implementations either produced
+// silhouettes for separator-free usernames OR leaked separator
+// characters into the result (e.g. ".U" for ".user").
+
+describe('computeUserInitials', () => {
+  it('uses segment initials when separators are present', () => {
+    expect(computeUserInitials('mary.kohli')).toBe('MK')
+    expect(computeUserInitials('mary_kohli')).toBe('MK')
+    expect(computeUserInitials('mary-kohli')).toBe('MK')
+  })
+
+  it('caps segment initials at 2 even with many separators', () => {
+    expect(computeUserInitials('a.b.c.d')).toBe('AB')
+  })
+
+  it('falls back to leading letters when no separators', () => {
+    expect(computeUserInitials('mkohli')).toBe('MK')
+    expect(computeUserInitials('alice')).toBe('AL')
+  })
+
+  it('returns a single letter for single-character usernames', () => {
+    expect(computeUserInitials('a')).toBe('A')
+  })
+
+  it('strips the @-domain before computing', () => {
+    expect(computeUserInitials('mary.kohli@example.com')).toBe('MK')
+    expect(computeUserInitials('mkohli@example.com')).toBe('MK')
+  })
+
+  it('uppercases the result', () => {
+    expect(computeUserInitials('alice')).toBe('AL')
+    expect(computeUserInitials('ALICE')).toBe('AL')
+    expect(computeUserInitials('aLiCe')).toBe('AL')
+  })
+
+  it('returns empty string for null/undefined/empty inputs', () => {
+    expect(computeUserInitials(null)).toBe('')
+    expect(computeUserInitials(undefined)).toBe('')
+    expect(computeUserInitials('')).toBe('')
+  })
+
+  it('handles consecutive separators without producing empty segments', () => {
+    expect(computeUserInitials('mary..kohli')).toBe('MK')
+    expect(computeUserInitials('mary__kohli')).toBe('MK')
+  })
+
+  it('handles email-only usernames with @ as the first character', () => {
+    expect(computeUserInitials('@example.com')).toBe('')
+  })
+
+  it('does not include separator characters in the fallback', () => {
+    // Leading/trailing separators must not leak into the avatar
+    // circle as ".U", "-A", "_O" — non-letters get filtered before
+    // the slice, not after.
+    expect(computeUserInitials('.user')).toBe('US')
+    expect(computeUserInitials('-admin')).toBe('AD')
+    expect(computeUserInitials('_ops')).toBe('OP')
+  })
+
+  it('takes leading letters of the segment, not the whole localPart, for trailing/leading separator inputs', () => {
+    // Single-segment inputs must fall back to leading letters of
+    // the SEGMENT, not the raw localPart — otherwise `'mary.'`
+    // returns `'MA'` from the wrong slice and inconsistency with
+    // `'mary.kohli'` shows up only on partial inputs.
+    expect(computeUserInitials('mary.')).toBe('MA')
+    expect(computeUserInitials('.mary')).toBe('MA')
+  })
+
+  it('returns empty for inputs with no letters', () => {
+    // The avatar circle has no glyph to render for separator-only,
+    // digit-only, or punctuation-only inputs — return `''` so the
+    // caller can fall back to a silhouette.
+    expect(computeUserInitials('..')).toBe('')
+    expect(computeUserInitials('123')).toBe('')
+    expect(computeUserInitials('_')).toBe('')
+    expect(computeUserInitials('---')).toBe('')
+  })
+
+  it('drops leading whitespace before computing initials', () => {
+    // Leading whitespace must not leak into the avatar circle as
+    // a pair of blank glyphs — the truthy `'  '` would defeat the
+    // caller's `{initials || <silhouette>}` fallback.
+    expect(computeUserInitials('  alice')).toBe('AL')
+    expect(computeUserInitials('\talice')).toBe('AL')
+  })
+
+  it('skips digits and punctuation interleaved with letters', () => {
+    expect(computeUserInitials('m1k')).toBe('MK')
+    expect(computeUserInitials('a$b$c')).toBe('AB')
+  })
+})
diff --git a/packages/k8s-ui/src/utils/user-initials.ts b/packages/k8s-ui/src/utils/user-initials.ts
new file mode 100644
index 000000000..4f547f26a
--- /dev/null
+++ b/packages/k8s-ui/src/utils/user-initials.ts
@@ -0,0 +1,41 @@
+/**
+ * Computes a 1- or 2-character avatar label for a username.
+ *
+ * Rules (in order):
+ *   1. Strip the @-domain from the local-part — domains never carry
+ *      useful identity for an in-app avatar.
+ *   2. Drop everything that isn't a letter (separators like `.`,
+ *      `_`, `-`, digits, punctuation). The avatar circle can only
+ *      render a meaningful glyph for letters; rendering `.U` or
+ *      `12` looks broken.
+ *   3. If the cleaned local-part contains separator-bounded
+ *      segments (`.`, `_`, `-`), use the first letter of each
+ *      segment (max 2). e.g. `"mary.kohli"` → `"MK"`.
+ *   4. Otherwise use the first 1-2 letters of the cleaned
+ *      local-part. e.g. `"mkohli"` → `"MK"`.
+ *   5. Always uppercase.
+ *   6. Returns `''` when no letters survive — the caller falls back
+ *      to a silhouette / `?` icon.
+ */
+export function computeUserInitials(username: string | null | undefined): string {
+  if (!username) return ''
+  const localPart = username.split('@')[0]
+  if (!localPart) return ''
+  // Split on the canonical separators first so segment-based
+  // initials still work, then drop any non-letter characters per
+  // segment so leading punctuation can't leak into the result.
+  const segments = localPart
+    .split(/[._-]/)
+    .map(s => s.replace(/[^a-zA-Z]/g, ''))
+    .filter(Boolean)
+  if (segments.length === 0) return ''
+  if (segments.length >= 2) {
+    return segments
+      .slice(0, 2)
+      .map(s => s[0].toUpperCase())
+      .join('')
+  }
+  // Single segment (no usable separators) — surface up to two
+  // leading letters so e.g. `mkohli` produces `MK` instead of `M`.
+  return segments[0].slice(0, 2).toUpperCase()
+}
diff --git a/web/src/components/UserMenu.tsx b/web/src/components/UserMenu.tsx
index ece485dae..cf10513ae 100644
--- a/web/src/components/UserMenu.tsx
+++ b/web/src/components/UserMenu.tsx
@@ -2,6 +2,7 @@ import { useState, useRef, useEffect, useCallback } from 'react'
 import { User, LogOut } from 'lucide-react'
 import { useAuthMe } from '../api/client'
 import { useQueryClient } from '@tanstack/react-query'
+import { computeUserInitials } from '@skyhook-io/k8s-ui/utils/user-initials'
 
 export function UserMenu() {
   const { data: authMe } = useAuthMe()
@@ -40,12 +41,7 @@ export function UserMenu() {
     return null
   }
 
-  const initials = authMe.username
-    .split('@')[0]
-    .split(/[._-]/)
-    .slice(0, 2)
-    .map(s => s[0]?.toUpperCase() || '')
-    .join('')
+  const initials = computeUserInitials(authMe.username)
 
   return (
     <div ref={menuRef} className="relative">
diff --git a/web/src/components/helm/ChartBrowser.tsx b/web/src/components/helm/ChartBrowser.tsx
index 784872149..333d4742f 100644
--- a/web/src/components/helm/ChartBrowser.tsx
+++ b/web/src/components/helm/ChartBrowser.tsx
@@ -425,7 +425,9 @@ function LocalChartCard({ chart, onSelect }: LocalChartCardProps) {
         )}
         <div className="flex-1 min-w-0">
           <div className="flex items-center gap-2">
-            <h4 className="text-sm font-medium text-theme-text-primary truncate">{chart.name}</h4>
+            <Tooltip content={chart.name} wrapperClassName="min-w-0 flex-1">
+              <h4 className="text-sm font-medium text-theme-text-primary truncate">{chart.name}</h4>
+            </Tooltip>
             {chart.deprecated && (
               <span className={clsx('px-1 py-0.5 text-[10px] rounded', SEVERITY_BADGE.warning)}>
                 deprecated
@@ -489,7 +491,9 @@ function ArtifactHubChartCard({ chart, onSelect }: ArtifactHubChartCardProps) {
 
         {/* Name and org */}
         <div className="flex-1 min-w-0">
-          <h4 className="text-sm font-medium text-theme-text-primary truncate">{chart.name}</h4>
+          <Tooltip content={chart.name} wrapperClassName="block">
+            <h4 className="text-sm font-medium text-theme-text-primary truncate">{chart.name}</h4>
+          </Tooltip>
           <div className="flex items-center gap-2 mt-0.5 text-xs text-theme-text-tertiary">
             <span className="flex items-center gap-1">
               <Building2 className="w-3 h-3" />