feat(design): surface phase PR 1 — Lucide icon migration + scale enforcement

Replaces every hand-inlined SVG in the chrome (60 across 15 files)
with Lucide components. Snaps icon sizes to the doc's 16/24 scale —
all icons in this pass land at 16. AppLogo wordmark stays as the
legitimate "custom app icon" exception per the doc; GraphView's <svg>
mount point for D3 stays as well.

Replaces emoji-as-icons in clear button-affordance cases with their
Lucide equivalents: ✕ → X (close/dismiss buttons across 8 files), ✓ →
Check (ProjectView task-advance button), 🎤 → Mic (ChatPanel voice
CTA), 📎 → Paperclip (ChatView context toggle), &uarr; → ArrowUp
(ChatInputBar Send), &times; → X (ChatPanel context-note remove), ☀/☾
→ Sun/Moon (AppHeader theme toggle).

Inline emoji punctuation in textual confirmation copy ("Saved ✓",
"Created ✓", `done: "✓"` status maps, `'✓' : '📄'` interpolations)
is left for surface-phase voice/tone touchups — replacing requires
structural template changes and is best done per-component.

Stroke weight stays at Lucide's default 2px; tightening to the doc's
1.5/1 is deferred per the surface-phase spec (option ii: drop-in +
scale enforcement).

Adds lucide-vue-next ^0.469.0 to frontend/package.json. Docker
rebuild handles the install.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/src/views/NoteViewerView.vue

@@ -9,6 +9,7 @@ import type { Note } from "@/types/note";
 import TagPill from "@/components/TagPill.vue";
 import TableOfContents from "@/components/TableOfContents.vue";
 import ShareDialog from "@/components/ShareDialog.vue";
+import { Clock, Pencil, Link as LinkIcon } from "lucide-vue-next";
 
 const route = useRoute();
 const router = useRouter();
@@ -238,12 +239,12 @@ async function convertToTask() {
         <h1 class="note-title">{{ store.currentNote.title || "Untitled" }}</h1>
         <p class="meta">
           <span class="meta-item">
-            <svg viewBox="0 0 24 24" width="13" height="13" fill="currentColor" aria-hidden="true"><path d="M11.99 2C6.47 2 2 6.48 2 12s4.47 10 9.99 10C17.52 22 22 17.52 22 12S17.52 2 11.99 2zM12 20c-4.42 0-8-3.58-8-8s3.58-8 8-8 8 3.58 8 8-3.58 8-8 8zm.5-13H11v6l5.25 3.15.75-1.23-4.5-2.67V7z"/></svg>
+            <Clock :size="16" />
             Updated {{ relativeTime(store.currentNote.updated_at) }}
           </span>
           <span class="meta-sep" aria-hidden="true">·</span>
           <span class="meta-item">
-            <svg viewBox="0 0 24 24" width="13" height="13" fill="currentColor" aria-hidden="true"><path d="M3 17.25V21h3.75L17.81 9.94l-3.75-3.75L3 17.25zM20.71 7.04c.39-.39.39-1.02 0-1.41l-2.34-2.34c-.39-.39-1.02-.39-1.41 0l-1.83 1.83 3.75 3.75 1.83-1.83z"/></svg>
+            <Pencil :size="16" />
             Created {{ relativeTime(store.currentNote.created_at) }}
           </span>
         </p>
@@ -265,7 +266,7 @@ async function convertToTask() {
 
         <div v-if="backlinks.length" class="backlinks">
           <h3 class="backlinks-heading">
-            <svg viewBox="0 0 24 24" width="15" height="15" fill="currentColor" aria-hidden="true"><path d="M3.9 12c0-1.71 1.39-3.1 3.1-3.1h4V7H7c-2.76 0-5 2.24-5 5s2.24 5 5 5h4v-1.9H7c-1.71 0-3.1-1.39-3.1-3.1zM8 13h8v-2H8v2zm9-6h-4v1.9h4c1.71 0 3.1 1.39 3.1 3.1s-1.39 3.1-3.1 3.1h-4V17h4c2.76 0 5-2.24 5-5s-2.24-5-5-5z"/></svg>
+            <LinkIcon :size="16" />
             Backlinks
             <span class="backlinks-count">{{ backlinks.length }}</span>
           </h3>