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/MarkdownInline.vue

@@ -1,10 +1,16 @@
 <script setup lang="ts">
 import type { InlineToken } from "../notes/markdown";
+import { tagTextClasses } from "../notes/colors";
 
-// Emphasis and code only. `[[wiki-links]]` were the one token type that needed a
+// Emphasis, code, and `#tags`. `[[wiki-links]]` were the one token type that needed a
 // router, a store and a resolver behind it; they are gone (note 2897), and so is all
 // of that.
-defineProps<{ tokens: InlineToken[] }>();
+//
+// `tagColors` maps a lowercased tag name to the colour stored on that label. Threaded
+// down from the card rather than looked up here, because this component renders text
+// and has no idea which note the text belongs to — and a tag the operator recoloured
+// must read the same here as it does on a chip.
+defineProps<{ tokens: InlineToken[]; tagColors?: Record<string, string> }>();
 </script>
 
 <!-- Rendered tightly (no whitespace between tokens) so a token's own leading/trailing
@@ -17,6 +23,8 @@ defineProps<{ tokens: InlineToken[] }>();
       v-else-if="t.type === 'code'"
       class="rounded bg-black/5 px-1 py-0.5 font-mono text-[0.85em] dark:bg-white/10"
       >{{ t.value }}</code
+    ><span v-else-if="t.type === 'tag'" class="font-medium" :class="tagTextClasses(t.value, tagColors)"
+      >#{{ t.value }}</span
     ><template v-else>{{ t.value }}</template></template
   ></template
 >

frontend/src/components/MarkdownText.vue

@@ -3,7 +3,13 @@ import { computed } from "vue";
 import { parseMarkdown } from "../notes/markdown";
 import MarkdownInline from "./MarkdownInline.vue";
 
-const props = defineProps<{ text: string; toggleable?: boolean }>();
+// `tagColors` is passed straight through to MarkdownInline — see there for why the
+// card owns the lookup rather than the renderer.
+const props = defineProps<{
+  text: string;
+  toggleable?: boolean;
+  tagColors?: Record<string, string>;
+}>();
 // Ticking a box rewrites a line of the note's body, which is a thing only the owner
 // of that note can do — so this renders the checkbox and hands the intent up rather
 // than reaching for the store itself. The card wires it; a read-only render does not
@@ -15,14 +21,20 @@ const blocks = computed(() => parseMarkdown(props.text));
 <template>
   <div class="space-y-1.5 break-words">
     <template v-for="(b, i) in blocks" :key="i">
-      <h3 v-if="b.type === 'h1'" class="text-base font-bold"><MarkdownInline :tokens="b.inline ?? []" /></h3>
-      <h4 v-else-if="b.type === 'h2'" class="text-sm font-bold"><MarkdownInline :tokens="b.inline ?? []" /></h4>
-      <h5 v-else-if="b.type === 'h3'" class="text-sm font-semibold"><MarkdownInline :tokens="b.inline ?? []" /></h5>
+      <h3 v-if="b.type === 'h1'" class="text-base font-bold">
+        <MarkdownInline :tokens="b.inline ?? []" :tag-colors="tagColors" />
+      </h3>
+      <h4 v-else-if="b.type === 'h2'" class="text-sm font-bold">
+        <MarkdownInline :tokens="b.inline ?? []" :tag-colors="tagColors" />
+      </h4>
+      <h5 v-else-if="b.type === 'h3'" class="text-sm font-semibold">
+        <MarkdownInline :tokens="b.inline ?? []" :tag-colors="tagColors" />
+      </h5>
       <blockquote
         v-else-if="b.type === 'quote'"
         class="whitespace-pre-wrap border-l-2 border-neutral-300 pl-2 text-neutral-600 dark:border-neutral-600 dark:text-neutral-400"
       >
-        <MarkdownInline :tokens="b.inline ?? []" />
+        <MarkdownInline :tokens="b.inline ?? []" :tag-colors="tagColors" />
       </blockquote>
       <div v-else-if="b.type === 'task'" class="flex flex-col gap-1">
         <div v-for="(it, j) in b.items ?? []" :key="j" class="flex items-start gap-2">
@@ -42,22 +54,22 @@ const blocks = computed(() => parseMarkdown(props.text));
             class="min-w-0 flex-1"
             :class="b.tasks?.[j]?.checked ? 'text-neutral-400 line-through' : ''"
           >
-            <MarkdownInline :tokens="it" />
+            <MarkdownInline :tokens="it" :tag-colors="tagColors" />
           </span>
         </div>
       </div>
       <ul v-else-if="b.type === 'ul'" class="list-disc space-y-0.5 pl-5">
-        <li v-for="(it, j) in b.items ?? []" :key="j"><MarkdownInline :tokens="it" /></li>
+        <li v-for="(it, j) in b.items ?? []" :key="j"><MarkdownInline :tokens="it" :tag-colors="tagColors" /></li>
       </ul>
       <ol v-else-if="b.type === 'ol'" class="list-decimal space-y-0.5 pl-5">
-        <li v-for="(it, j) in b.items ?? []" :key="j"><MarkdownInline :tokens="it" /></li>
+        <li v-for="(it, j) in b.items ?? []" :key="j"><MarkdownInline :tokens="it" :tag-colors="tagColors" /></li>
       </ol>
       <pre
         v-else-if="b.type === 'pre'"
         class="overflow-x-auto whitespace-pre-wrap rounded-md bg-black/5 p-2 font-mono text-xs dark:bg-white/10"
         >{{ b.value ?? "" }}</pre
       >
-      <p v-else class="whitespace-pre-wrap"><MarkdownInline :tokens="b.inline ?? []" /></p>
+      <p v-else class="whitespace-pre-wrap"><MarkdownInline :tokens="b.inline ?? []" :tag-colors="tagColors" /></p>
     </template>
   </div>
 </template>

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"

frontend/src/components/NoteEditor.vue

@@ -613,7 +613,10 @@ function revPreview(rev: NoteRevision): string {
             class="inline-flex items-center gap-1 rounded-full px-2 py-0.5 text-xs"
             :class="labelChip(lb)"
           >
-            {{ lb.via_tag ? "#" + lb.name : lb.name }}
+            <!-- `#` on every chip, matching the card. This row still lists the tags
+                 the BODY owns too — it is the control surface, and `via_tag` is what
+                 decides whether there is a cross to remove one with. -->
+            #{{ lb.name }}
             <button
               v-if="!lb.via_tag"
               type="button"

frontend/src/notes/colors.ts

@@ -57,6 +57,43 @@ export const LABEL_CHIP_CLASSES: Record<NoteColor, string> = {
   gray: "bg-neutral-200 text-neutral-700 dark:bg-neutral-700 dark:text-neutral-200 ring-1 ring-inset ring-neutral-700/60 dark:ring-neutral-200/60",
 };
 
+// The ink for a `#tag` drawn where it was typed, rather than repeated as a chip.
+//
+// ONE Tailwind step deeper than LABEL_CHIP_CLASSES' text, and the difference is not a
+// stylistic one. A chip carries its own `-100` fill, so its text has exactly one
+// background to read against. Inline text sits on whatever the CARD is — which
+// includes a gray-tagged card at `neutral-200`, where the chip's `-700` measured 3.98
+// (green), 4.11 (orange) and 4.34 (teal), all under the 4.5 body text needs. At `-800`
+// every hue lands between 5.63 and 12.01 in light, and `-300` gives 7.20 to 10.84 in
+// dark, measured against every fill in NOTE_CARD_CLASSES_STRONG and every generated
+// fill. One step for all ten beats three per-hue exceptions.
+//
+// Mirrored in NoteTint.kt as `lightTagInk` / `darkTagInk`.
+export const TAG_TEXT_CLASSES: Record<NoteColor, string> = {
+  default: "text-neutral-700 dark:text-neutral-300",
+  red: "text-red-800 dark:text-red-300",
+  orange: "text-orange-800 dark:text-orange-300",
+  yellow: "text-amber-800 dark:text-amber-300",
+  green: "text-green-800 dark:text-green-300",
+  teal: "text-teal-800 dark:text-teal-300",
+  blue: "text-blue-800 dark:text-blue-300",
+  purple: "text-purple-800 dark:text-purple-300",
+  pink: "text-pink-800 dark:text-pink-300",
+  gray: "text-neutral-800 dark:text-neutral-200",
+};
+
+/**
+ * The classes for one `#tag` in a note's own words.
+ *
+ * `picked` maps a lowercased tag name to the colour stored on that label, so a tag the
+ * operator has recoloured reads the same inline as it does on a chip. A tag the note
+ * does not carry as a label yet — just typed, not yet derived — is not in the map, and
+ * `resolveLabelColor` derives one from the name exactly as the chip would have.
+ */
+export function tagTextClasses(name: string, picked?: Record<string, string>): string {
+  return TAG_TEXT_CLASSES[resolveLabelColor({ name, color: picked?.[name.toLowerCase()] })];
+}
+
 // Solid fills for graph nodes (SVG needs concrete colors, not Tailwind bg classes).
 // Mid-tone hues read on both the light and dark graph background.
 export const NOTE_NODE_FILL: Record<NoteColor, string> = {

frontend/src/notes/markdown.ts

@@ -7,7 +7,9 @@
 // a heading.
 
 export interface InlineToken {
-  type: "text" | "bold" | "italic" | "code";
+  /** `tag` carries the NAME, without the leading `#` — it is both what gets looked up
+   *  for a colour and what is rendered, so the renderer puts the `#` back. */
+  type: "text" | "bold" | "italic" | "code" | "tag";
   value: string;
 }
 
@@ -37,7 +39,22 @@ export interface TaskMeta {
 // `[[wiki-links]]` used to lead this alternation. They are gone (note 2897) — this is
 // a capture-and-recall surface, and a linking system is organization. `[[text]]` now
 // renders as the literal characters someone typed, which is what it always was.
-const INLINE_RE = /(`[^`]+`)|(\*\*[^*]+\*\*)|(\*[^*]+\*)|(_[^_]+_)/g;
+// `#tag` is LAST in the alternation and that is load-bearing twice over. JS tries
+// alternatives left to right, so a `#tag` inside backticks is claimed by `code` first
+// and stays literal — matching the core, where a fenced block's contents are code.
+// And a tag is the one token here that is not delimiter-based, so it must not get a
+// chance to start inside `**bold #x**`.
+//
+// The grammar MIRRORS `line_tags` in core/src/local/derive.rs, which is the definition:
+// a `#` at a word boundary (the preceding character is neither a tag character nor
+// another `#`, so `a#b` and `##x` are not tags), a letter immediately after it, then
+// alphanumerics, `_` and `-`. Rust's `is_alphanumeric` is `Alphabetic | N`, hence the
+// property escapes rather than `\w` — and hence the `u` flag.
+//
+// A heading cannot collide with this: `parseMarkdown` requires a space after the `#`s,
+// which `#tag` by definition does not have.
+const INLINE_RE =
+  /(`[^`]+`)|(\*\*[^*]+\*\*)|(\*[^*]+\*)|(_[^_]+_)|((?<![\p{Alphabetic}\p{N}_#-])#\p{Alphabetic}[\p{Alphabetic}\p{N}_-]*)/gu;
 
 export function parseInline(text: string): InlineToken[] {
   const tokens: InlineToken[] = [];
@@ -49,6 +66,7 @@ export function parseInline(text: string): InlineToken[] {
     const raw = m[0];
     if (m[1]) tokens.push({ type: "code", value: raw.slice(1, -1) });
     else if (m[2]) tokens.push({ type: "bold", value: raw.slice(2, -2) });
+    else if (m[5]) tokens.push({ type: "tag", value: raw.slice(1) });
     else tokens.push({ type: "italic", value: raw.slice(1, -1) });
     last = m.index + raw.length;
   }

frontend/src/stores/notes.ts

@@ -21,8 +21,13 @@ export interface NoteLabel {
   id: string;
   name: string;
   color: string;
-  // True when this label is attached because of a #tag in the note body (kept in
-  // sync with the text); false = added manually via the picker.
+  // True when the label is backed by text STILL IN THE BODY — a `#tag` written
+  // mid-sentence, kept in sync with those words. False covers both a label added
+  // through the picker and a tag lifted off a line of its own (M311), which is why
+  // it is also what decides whether a chip can be removed with a cross.
+  //
+  // The card reads it the other way round: a true here means the body is already
+  // showing this tag, so the chip would be the second copy and is not drawn.
   via_tag: boolean;
 }