fix(landing): design audit fixes — hamburger menu, dead links, branding, spacing (#117)

* fix(landing): design audit fixes — hamburger menu, dead links, branding, spacing

- Add mobile hamburger menu with animated open/close and click-outside dismiss
- Create Privacy and Terms pages (footer links were dead # anchors)
- Change "Decision Tree Platform" to "AI-Powered Troubleshooting for MSPs" on login, register, and HTML title
- Fix register page icon color (was red/coral via CSS invert, now uses BrandLogo directly)
- Replace "0 Ticket Notes Written by Hand" stat with "100% Auto-Generated Documentation"
- Increase nav link touch targets to 44px minimum
- Fix heading hierarchy: section titles are now <h2>, standardize H3 to 1.25rem
- Tighten section spacing (6rem → 4rem padding, remove extra 5rem spacer)
- Add color-scheme: dark to HTML element
- Replace all transition: all with specific properties (10 occurrences)
- Fix loading ellipsis (... → …)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(mobile): responsive modals + landing preview overflow

- PrepareSessionModal: bottom-sheet on mobile, centered on desktop
- IntakeFormModal: bottom-sheet on mobile, responsive padding
- ShareTreeModal: bottom-sheet on mobile, full-width on small screens
- Landing preview: hide URL bar and window controls on mobile (<900px)
  to prevent 189px horizontal overflow

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(mobile): collapse search bar to icon on mobile

On mobile (<640px), the full search bar with placeholder text and ⌘K
badge was taking too much space in the topbar. Now shows just a
magnifying glass icon that opens the same command palette on tap.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: chihlasm <michael@resolutionflow.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/components/procedural/IntakeFormModal.tsx

@@ -212,8 +212,8 @@ export function IntakeFormModal({ isOpen, fields, treeName, onSubmit, onCancel }
   }
 
   return (
-    <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/60 backdrop-blur-xs">
-      <div className="mx-4 w-full max-w-lg rounded-2xl border border-border bg-background shadow-xl">
+    <div className="fixed inset-0 z-50 flex items-end justify-center p-0 sm:items-center sm:p-4 bg-black/60 backdrop-blur-xs">
+      <div className="w-full max-w-full rounded-t-2xl border border-border bg-background shadow-xl sm:max-w-lg sm:rounded-2xl">
         {/* Header */}
         <div className="border-b border-border px-6 py-4">
           <h2 className="text-lg font-semibold text-foreground">Project Information</h2>
@@ -224,7 +224,7 @@ export function IntakeFormModal({ isOpen, fields, treeName, onSubmit, onCancel }
 
         {/* Form */}
         <form onSubmit={handleSubmit}>
-          <div className="max-h-[60vh] space-y-4 overflow-y-auto px-6 py-4">
+          <div className="max-h-[70vh] space-y-4 overflow-y-auto px-4 py-4 sm:max-h-[60vh] sm:px-6">
             {Array.from(groups.entries()).map(([groupName, groupFields]) => (
               <div key={groupName}>
                 {groupName && (

frontend/src/components/procedural/PrepareSessionModal.tsx

@@ -88,9 +88,9 @@ export function PrepareSessionModal({
   }
 
   return (
-    <div className="fixed inset-0 z-50 flex items-center justify-center">
+    <div className="fixed inset-0 z-50 flex items-end justify-center p-0 sm:items-center sm:p-4">
       <div className="absolute inset-0 bg-background/60 backdrop-blur-xs" onClick={onClose} />
-      <div className="relative w-full max-w-lg rounded-2xl border border-border bg-card shadow-2xl">
+      <div className="relative w-full max-w-full rounded-t-2xl border border-border bg-card shadow-2xl sm:max-w-lg sm:rounded-2xl">
         {/* Header */}
         <div className="flex items-center justify-between border-b border-border px-5 py-4">
           <div className="flex items-center gap-2">
@@ -106,7 +106,7 @@ export function PrepareSessionModal({
         </div>
 
         {/* Body */}
-        <div className="max-h-[60vh] overflow-y-auto p-5 space-y-5">
+        <div className="max-h-[70vh] overflow-y-auto p-4 space-y-5 sm:max-h-[60vh] sm:p-5">
           {/* Flow name */}
           <div className="rounded-lg bg-accent px-3 py-2">
             <p className="text-xs text-muted-foreground">Flow</p>