feat(api): links routes

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

lib/api/routes/links.js

@@ -0,0 +1,58 @@
+import { Router } from 'express';
+import { z } from 'zod';
+import * as repo from '../../db/repos/links.js';
+import { validate } from '../validate.js';
+import { requireWrite } from '../cap.js';
+import { asyncWrap } from '../errors.js';
+
+const ENTITY_TYPES = ['space','project','task','page','ref','resource','source_doc','conversation'];
+
+const createSchema = z.object({
+  from_type: z.enum(ENTITY_TYPES),
+  from_id: z.string().uuid(),
+  to_type: z.enum(ENTITY_TYPES),
+  to_id: z.string().uuid(),
+  relation: z.string().min(1).max(64).optional()
+});
+
+const endpointParams = z.object({
+  type: z.enum(ENTITY_TYPES),
+  id: z.string().uuid()
+});
+
+const idParams = z.object({ id: z.string().uuid() });
+
+export const router = Router();
+
+router.post('/',
+  requireWrite('link'),
+  validate({ body: createSchema }),
+  asyncWrap(async (req, res) => {
+    const { from_type, from_id, to_type, to_id, relation } = req.body;
+    const row = await repo.create(from_type, from_id, to_type, to_id, relation);
+    res.status(201).json(row);
+  })
+);
+
+router.get('/from/:type/:id',
+  validate({ params: endpointParams }),
+  asyncWrap(async (req, res) => {
+    res.json(await repo.listFrom(req.params.type, req.params.id));
+  })
+);
+
+router.get('/to/:type/:id',
+  validate({ params: endpointParams }),
+  asyncWrap(async (req, res) => {
+    res.json(await repo.listTo(req.params.type, req.params.id));
+  })
+);
+
+router.delete('/:id',
+  requireWrite('link'),
+  validate({ params: idParams }),
+  asyncWrap(async (req, res) => {
+    await repo.remove(req.params.id);
+    res.status(204).end();
+  })
+);