diff --git a/docs/architecture/release-pipeline.md b/docs/architecture/release-pipeline.md
index 97028a772..88ef4fd59 100644
--- a/docs/architecture/release-pipeline.md
+++ b/docs/architecture/release-pipeline.md
@@ -27,7 +27,7 @@ chosen deliberately by bumping `package.json`.
 | GitHub release body | (tag build) | via `extract-changelog-section.mjs --public` |
 | Telegram announcement | `release:notes:telegram` | stdout |
 | Reddit announcement | `release:notes:reddit` | stdout |
-| Highlight cards | `release:cards:generate` | `dist/release-highlight-cards/<vX-Y>/` |
+| Highlight cards | `release:cards:generate` | `dist/release-highlight-cards/v<version>/` |
 | Screenshots | `release:screenshots` | `apps/website/public/blog/<vX-Y>/screenshots/` |
 
 ### The ordering constraint that matters
@@ -100,7 +100,11 @@ card into the website tree is a deliberate manual act.
 
 A release with no `highlight:` notes is not an error: the hero card is still
 rendered and the run exits 0. An internal-only release has nothing public to
-put on a card and exits 0 having written nothing.
+put on a card and exits 0, first clearing any cards an earlier run of the same
+version left behind. An **empty** `.changes/` directory is a different thing
+and does fail: it almost always means this step ran after `--consume`, and
+reporting that as "internal-only" would hide the one ordering mistake the
+pipeline is built to prevent.
 
 ## Draft verification
 
diff --git a/tools/release/generate-highlight-cards.mjs b/tools/release/generate-highlight-cards.mjs
index 85c788176..6628de4c1 100644
--- a/tools/release/generate-highlight-cards.mjs
+++ b/tools/release/generate-highlight-cards.mjs
@@ -140,6 +140,29 @@ async function prepareShotOverlay(screenshotPath) {
     return { input: cropped, left: SHOT_LEFT, top: SHOT_TOP };
 }
 
+/**
+ * Removes the cards a previous run of THIS generator left in `outputDir`, so a
+ * renamed, dropped, or newly-internal highlight cannot leave a stale image
+ * sitting there waiting to be published. Only files matching what this tool
+ * writes are touched; anything else in the directory is left alone.
+ *
+ * @param {string} outputDir
+ * @returns {string[]} removed filenames
+ */
+export function removeStaleCards(outputDir) {
+    if (!existsSync(outputDir)) {
+        return [];
+    }
+
+    const stale = readdirSync(outputDir).filter(isOwnedCardFile);
+
+    for (const entry of stale) {
+        rmSync(path.join(outputDir, entry));
+    }
+
+    return stale;
+}
+
 /**
  * @param {{ feature: object[], hero: object }} plan
  * @param {string} version
@@ -148,16 +171,7 @@ async function prepareShotOverlay(screenshotPath) {
  */
 export async function renderCards(plan, version, outputDir) {
     mkdirSync(outputDir, { recursive: true });
-
-    // Remove the cards a previous run of THIS generator left behind, so a
-    // renamed or dropped highlight cannot leave a stale image sitting beside
-    // the current set waiting to be published. Only files matching what this
-    // tool writes are touched; anything else in the directory is left alone.
-    for (const entry of readdirSync(outputDir)) {
-        if (isOwnedCardFile(entry)) {
-            rmSync(path.join(outputDir, entry));
-        }
-    }
+    removeStaleCards(outputDir);
 
     const written = [];
 
@@ -210,6 +224,22 @@ async function main() {
         process.exit(1);
     }
 
+    // An empty directory is not an internal-only release: it is almost always
+    // this step running AFTER `--consume` deleted the notes, which is the one
+    // ordering mistake the whole pipeline warns about. Reporting it as
+    // "internal-only" would hide the mistake and quietly ship no cards at all.
+    if (notes.length === 0) {
+        console.error(
+            [
+                `No notes found in ${path.relative(workspaceRoot, notesDir)}/.`,
+                'Cards are built from `highlight:`, which exists only in the note',
+                'files — if `build-release-notes.mjs --consume` already ran, that',
+                'metadata is gone. Render cards before consuming.',
+            ].join(' ')
+        );
+        process.exit(1);
+    }
+
     const slug = releaseSlug(options.version);
     const screenshotsDir = path.join(
         workspaceRoot,
@@ -223,6 +253,14 @@ async function main() {
         screenshotsDir,
         theme: options.theme,
     });
+    // Keyed by the exact version, not the minor slug: 0.24.0 and 0.24.1 share
+    // a blog post but not a card set, and mixing them in one directory invites
+    // publishing the previous patch's card.
+    const outputDir = path.resolve(
+        workspaceRoot,
+        options.out ??
+            path.join('dist/release-highlight-cards', `v${options.version}`)
+    );
 
     // Neither shape below is an error: an internal-only release is legal, and
     // a release nobody marked a highlight on still deserves its hero card.
@@ -232,6 +270,19 @@ async function main() {
             'Internal-only release: no public change to put on a card.'
         );
 
+        // A release that turned internal-only after cards were already made
+        // for this exact version must not leave them behind. `--dry-run`
+        // deletes nothing.
+        if (options.mode === 'generate') {
+            const removed = removeStaleCards(outputDir);
+
+            if (removed.length > 0) {
+                console.log(
+                    `Removed ${removed.length} card(s) left by an earlier run of v${options.version}.`
+                );
+            }
+        }
+
         return;
     }
 
@@ -256,15 +307,6 @@ async function main() {
         process.exit(1);
     }
 
-    // Keyed by the exact version, not the minor slug: 0.24.0 and 0.24.1 share
-    // a blog post but not a card set, and mixing them in one directory invites
-    // publishing the previous patch's card.
-    const outputDir = path.resolve(
-        workspaceRoot,
-        options.out ??
-            path.join('dist/release-highlight-cards', `v${options.version}`)
-    );
-
     console.log(`${plan.feature.length} highlight card(s) + hero for v${options.version}:`);
     for (const job of plan.feature) {
         const shot = job.screenshotPath
@@ -280,14 +322,14 @@ async function main() {
         return;
     }
 
-    if (existsSync(outputDir)) {
-        const stale = readdirSync(outputDir).filter(isOwnedCardFile);
+    const stale = existsSync(outputDir)
+        ? readdirSync(outputDir).filter(isOwnedCardFile)
+        : [];
 
-        if (stale.length > 0) {
-            console.log(
-                `Replacing ${stale.length} card(s) from a previous run in the same directory.`
-            );
-        }
+    if (stale.length > 0) {
+        console.log(
+            `Replacing ${stale.length} card(s) from a previous run in the same directory.`
+        );
     }
 
     const written = await renderCards(plan, options.version, outputDir);
diff --git a/tools/release/highlight-cards.mjs b/tools/release/highlight-cards.mjs
index 149b9152a..fde1c13f1 100644
--- a/tools/release/highlight-cards.mjs
+++ b/tools/release/highlight-cards.mjs
@@ -119,12 +119,23 @@ export function planHighlightCards(notes, options) {
         .flatMap((group) => group.notes);
     const highlights = ordered.filter((note) => note.highlight);
 
+    const takenSlugs = new Set();
+
     const feature = highlights.map((note) => {
         // Named after the note file, never the screenshot slug: filenames are
         // unique within `.changes/`, while two highlights may legitimately
         // point at the same manifest shot — naming cards after it would let
         // one silently overwrite the other.
-        const slug = path.basename(note.sourcePath, '.md').toLowerCase();
+        const base = cardSlug(path.basename(note.sourcePath, '.md'));
+        // Normalizing can collapse two distinct names onto one, so uniqueness
+        // is re-established here rather than assumed.
+        let slug = base;
+
+        for (let suffix = 2; takenSlugs.has(slug); suffix += 1) {
+            slug = `${base}-${suffix}`;
+        }
+
+        takenSlugs.add(slug);
 
         return {
             slug,
@@ -169,6 +180,24 @@ export function isOwnedCardFile(fileName) {
     );
 }
 
+/**
+ * Every emitted filename must satisfy isOwnedCardFile(), or a later run cannot
+ * reclaim the card it wrote. Note filenames are conventionally lowercase slugs
+ * but nothing enforces it, so normalize rather than trust: `player_new-ui.md`
+ * would otherwise produce a card no cleanup pass can ever remove.
+ *
+ * @param {string} noteBaseName note filename without its `.md` extension
+ * @returns {string}
+ */
+export function cardSlug(noteBaseName) {
+    const normalized = noteBaseName
+        .toLowerCase()
+        .replace(/[^a-z0-9]+/g, '-')
+        .replace(/^-+|-+$/g, '');
+
+    return normalized || 'note';
+}
+
 function backgroundDefs() {
     return [
         '<defs>',
diff --git a/tools/release/highlight-cards.test.mjs b/tools/release/highlight-cards.test.mjs
index c82cb2415..90e906601 100644
--- a/tools/release/highlight-cards.test.mjs
+++ b/tools/release/highlight-cards.test.mjs
@@ -9,6 +9,8 @@ import {
 } from 'node:fs';
 import { tmpdir } from 'node:os';
 import path from 'node:path';
+import { spawnSync } from 'node:child_process';
+import { fileURLToPath } from 'node:url';
 import { after, describe, it } from 'node:test';
 import sharp from 'sharp';
 
@@ -26,6 +28,7 @@ import {
 } from './highlight-cards.mjs';
 import {
     parseCardArguments,
+    removeStaleCards,
     renderCards,
 } from './generate-highlight-cards.mjs';
 
@@ -178,6 +181,32 @@ describe('planHighlightCards', () => {
         );
     });
 
+    it('emits only filenames the ownership predicate can reclaim', () => {
+        // Nothing enforces the lowercase-slug filename convention, and a card
+        // the cleanup pass cannot recognize is a card that lives forever.
+        const plan = planHighlightCards(
+            [
+                note({
+                    highlight: 'New UI',
+                    sourcePath: '.changes/Player_New-UI.md',
+                }),
+                note({
+                    highlight: 'Other',
+                    sourcePath: '.changes/player.new.ui.md',
+                }),
+            ],
+            planOptions
+        );
+
+        assert.deepEqual(
+            plan.feature.map((job) => job.fileName),
+            ['card-player-new-ui.png', 'card-player-new-ui-2.png']
+        );
+        for (const job of plan.feature) {
+            assert.equal(isOwnedCardFile(job.fileName), true, job.fileName);
+        }
+    });
+
     it('claims only the files it writes', () => {
         for (const owned of ['card-playback-up-next.png', 'hero.png', 'hero.jpg']) {
             assert.equal(isOwnedCardFile(owned), true, owned);
@@ -400,6 +429,23 @@ describe('renderCards', () => {
         }
     });
 
+    it('removeStaleCards tolerates a missing directory and reports what it took', () => {
+        const outputDir = path.join(makeTempDir(), 'never-created');
+
+        assert.deepEqual(removeStaleCards(outputDir), []);
+
+        mkdirSync(outputDir, { recursive: true });
+        writeFileSync(path.join(outputDir, 'card-gone.png'), 'x');
+        writeFileSync(path.join(outputDir, 'hero.jpg'), 'x');
+        writeFileSync(path.join(outputDir, 'keep.txt'), 'x');
+
+        assert.deepEqual(removeStaleCards(outputDir).sort(), [
+            'card-gone.png',
+            'hero.jpg',
+        ]);
+        assert.deepEqual(readdirSync(outputDir), ['keep.txt']);
+    });
+
     it('removes its own stale cards but leaves other files alone', async () => {
         const outputDir = path.join(makeTempDir(), 'cards');
 
@@ -424,3 +470,97 @@ describe('renderCards', () => {
         ]);
     });
 });
+
+describe('generate-highlight-cards CLI', () => {
+    const CLI = path.resolve(
+        path.dirname(fileURLToPath(import.meta.url)),
+        'generate-highlight-cards.mjs'
+    );
+
+    function runCli(args) {
+        const result = spawnSync(process.execPath, [CLI, ...args], {
+            encoding: 'utf8',
+            stdio: ['ignore', 'pipe', 'pipe'],
+        });
+
+        return {
+            status: result.status ?? 1,
+            stdout: result.stdout ?? '',
+            stderr: result.stderr ?? '',
+        };
+    }
+
+    it('fails on an empty notes directory instead of calling it internal-only', () => {
+        // The realistic cause is running this step after `--consume`, which
+        // deleted the notes; silently reporting "internal-only" would hide it.
+        const emptyDir = makeTempDir();
+        const result = runCli([
+            '--generate',
+            '--version',
+            '0.24.0',
+            '--dir',
+            emptyDir,
+            '--out',
+            path.join(makeTempDir(), 'cards'),
+        ]);
+
+        assert.equal(result.status, 1);
+        assert.match(result.stderr, /No notes found/);
+        assert.match(result.stderr, /Render cards before consuming/);
+        assert.doesNotMatch(result.stderr, /Internal-only/);
+    });
+
+    it('clears stale cards when a release becomes internal-only', () => {
+        const notesDir = makeTempDir();
+        const outputDir = path.join(makeTempDir(), 'cards');
+
+        writeFileSync(
+            path.join(notesDir, 'deps-bump.md'),
+            '---\ntype: internal\narea: deps\n---\n\nBumped a parser.\n',
+            'utf8'
+        );
+        mkdirSync(outputDir, { recursive: true });
+        writeFileSync(path.join(outputDir, 'card-old-feature.png'), 'stale');
+        writeFileSync(path.join(outputDir, 'keep.txt'), 'mine');
+
+        const result = runCli([
+            '--generate',
+            '--version',
+            '0.24.0',
+            '--dir',
+            notesDir,
+            '--out',
+            outputDir,
+        ]);
+
+        assert.equal(result.status, 0);
+        assert.match(result.stderr, /Internal-only release/);
+        assert.deepEqual(readdirSync(outputDir), ['keep.txt']);
+    });
+
+    it('leaves stale cards untouched in dry-run mode', () => {
+        const notesDir = makeTempDir();
+        const outputDir = path.join(makeTempDir(), 'cards');
+
+        writeFileSync(
+            path.join(notesDir, 'deps-bump.md'),
+            '---\ntype: internal\narea: deps\n---\n\nBumped a parser.\n',
+            'utf8'
+        );
+        mkdirSync(outputDir, { recursive: true });
+        writeFileSync(path.join(outputDir, 'card-old-feature.png'), 'stale');
+
+        const result = runCli([
+            '--dry-run',
+            '--version',
+            '0.24.0',
+            '--dir',
+            notesDir,
+            '--out',
+            outputDir,
+        ]);
+
+        assert.equal(result.status, 0);
+        assert.deepEqual(readdirSync(outputDir), ['card-old-feature.png']);
+    });
+});