feat: support both ticket link directions (KAN-12)

tests/Fixtures/ticket-detail.mjs

@@ -398,6 +398,11 @@ if (serve) {
                 } else {
                     params.delete('noLinks');
                     params.delete('linkRejected');
+                    if (data.link_direction === 'counterpart') {
+                        params.set('incoming', '1');
+                    } else {
+                        params.delete('incoming');
+                    }
                 }
             } else {
                 assert.ok(
@@ -486,6 +491,8 @@ if (serve) {
             return result.body.split('id="main-content"')[1];
         };
         const html = await render();
+        assert.ok(html.includes('id="link_direction"'));
+        assert.ok(html.includes('Blocked by'));
         for (const text of [
             ticket.title,
             'Keep every existing ticket action available.',

tests/Fixtures/ticket-relationships-browser.mjs

@@ -70,6 +70,15 @@ try {
             assert.equal(await collapse.getAttribute('aria-expanded'), 'true');
             await control('Link type').focus();
             await page.keyboard.press('Tab');
+            assert.equal(
+                await control('This ticket').evaluate(
+                    (el) =>
+                        el === document.activeElement &&
+                        el.matches(':focus-visible'),
+                ),
+                true,
+            );
+            await page.keyboard.press('Tab');
             assert.equal(
                 await control('Linked ticket').evaluate(
                     (el) =>
@@ -118,6 +127,7 @@ try {
     await save().click();
     assert.deepEqual((await request).postDataJSON(), {
         ticket_link_type_id: 1,
+        link_direction: 'source',
         linked_ticket_id: 41,
     });
     await section().getByText('Outgoing', { exact: true }).waitFor();
@@ -141,6 +151,25 @@ try {
         document.activeElement?.textContent.includes('Linked tickets'),
     );
 
+    await visit('?noLinks');
+    await control('This ticket').selectOption('counterpart');
+    await control('Linked ticket').selectOption('41');
+    await section()
+        .locator('form')
+        .last()
+        .getByText('Blocked by', { exact: true })
+        .waitFor();
+    request = page.waitForRequest(
+        (r) => r.method() === 'POST' && r.url().endsWith('/links'),
+    );
+    await save().click();
+    assert.deepEqual((await request).postDataJSON(), {
+        ticket_link_type_id: 1,
+        link_direction: 'counterpart',
+        linked_ticket_id: 41,
+    });
+    await section().getByText('Incoming', { exact: true }).waitFor();
+
     await visit('?rejectLink');
     await control('Linked ticket').selectOption('41');
     await save().click();