board: a tag in the prose is coloured where it sits, not printed twice

A tagged note was showing its tag twice — once where it was typed, once as a
chip — and the duplicate was the loud copy. Now the chip row carries only what
the body cannot say (a tag lifted off its own line, a label from the picker),
and a `#tag` left mid-sentence is tinted in place.

Which characters are a tag is asked of the CORE, the way the card already asks
it which lines are checklist items: `extract_tag_spans` keeps the spans
`extract_tags` throws away, and `body_tags` hands them to Kotlin. Offsets are
UTF-16 code units, because `AnnotatedString` and JS both index that way and a
char index lands mid-token the first time somebody writes an emoji. The web
keeps its own matcher in markdown.ts, mirroring `line_tags` case for case.

The inline ink is its own table, one Tailwind step deeper than the chip's. A
chip brings its own -100 fill and reads against that alone; inline text sits on
whatever the card is, including a gray-tagged card at neutral-200 — where the
chip's -700 measured 3.98 (green), 4.11 (orange) and 4.34 (teal), under the 4.5
body text needs. At -800/-300 every hue lands 5.63-12.01 light and 7.20-10.84
dark across every palette and generated fill.

Chips now carry the `#` on every surface. The via_tag branch that used to
decide it is gone from the card, and Android's row said no hash at all.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

frontend/src/components/NoteCard.vue

@@ -197,6 +197,23 @@ function labelChip(label: { name: string; color: string }): string {
   return LABEL_CHIP_CLASSES[resolveLabelColor(label)] ?? LABEL_CHIP_CLASSES.default;
 }
 
+// Only the tags the BODY is not already showing. `via_tag` means exactly "backed by
+// text still in the note" since M311, so a chip for one printed the same tag twice —
+// once where it was typed, once in this row — and the loud copy was the duplicate. A
+// tag left in prose is tinted where it sits instead (MarkdownInline). What survives
+// here is what the body cannot say: a tag lifted off its own line, and a label added
+// through the picker.
+const chipLabels = computed(() => props.note.labels.filter((lb) => !lb.via_tag));
+
+// The colour the operator stored for each of this note's tags, keyed by lowercased
+// name — what MarkdownInline needs to tint a `#tag` the same as its chip would be.
+// Lowercased because tags dedupe case-insensitively, so `#Todo` and `#todo` are one.
+const tagColors = computed<Record<string, string>>(() => {
+  const map: Record<string, string> = {};
+  for (const lb of props.note.labels) map[lb.name.toLowerCase()] = lb.color;
+  return map;
+});
+
 // Per-card color popover (recolor without opening the editor).
 const colorOpen = ref(false);
 
@@ -267,13 +284,19 @@ onBeforeUnmount(() => document.removeEventListener("mousedown", onDocMousedown))
          Above the image and the body rather than beside them, because the body's first
          line is the note's NAME (M13 steps 3 and 4) and a chip floated next to it would
          compete with the thing that identifies the note. -->
-    <div v-if="note.labels.length" class="mb-2 flex flex-wrap gap-1">
+    <div v-if="chipLabels.length" class="mb-2 flex flex-wrap gap-1">
+      <!-- Every chip carries the `#`, not just the ones derived from body text. That
+           branch used to distinguish a `#tag` from a picker label; it cannot any more,
+           because a tag whose text is still in the body no longer reaches this row at
+           all. What is left is all the same thing to the eye and to the vocabulary —
+           and the hash is what keeps a lifted chip reading as the `#todo` somebody
+           typed. Android's row says the same, which it did not before. -->
       <span
-        v-for="lb in note.labels"
+        v-for="lb in chipLabels"
         :key="lb.id"
         class="rounded-full px-2 py-0.5 text-xs"
         :class="labelChip(lb)"
-        >{{ lb.via_tag ? "#" + lb.name : lb.name }}</span
+        >#{{ lb.name }}</span
       >
     </div>
 
@@ -314,7 +337,7 @@ onBeforeUnmount(() => document.removeEventListener("mousedown", onDocMousedown))
            blank and the link is never unreachable. -->
       <LinkPreview v-if="loneUrlPreview" :preview="loneUrlPreview" />
       <div v-else-if="note.body" class="text-sm text-neutral-700 dark:text-neutral-300">
-        <MarkdownText :text="bodyPreview" toggleable @toggle="toggleTask" />
+        <MarkdownText :text="bodyPreview" :tag-colors="tagColors" toggleable @toggle="toggleTask" />
       </div>
       <p
         v-if="!note.body && !note.items.length && !note.attachments.length"