feat: add memory.patch, trim memory.get, unify the memory write path

memory.get no longer returns the embedding and content_tsv
----------------------------------------------------------
It used a bare select() and returned the raw DB row, while memory.list
and memory.search already projected an explicit 9-field shape. On a
~13k-char memory those two internal columns were 55% of the response
and pushed it past the MCP tool-output cap, so large memories could not
be fetched inline at all. memory.get now returns the same 9 fields as
its siblings; user_id is still selected for the authorization check and
stripped before responding.

memory.patch
------------
memory.update only accepts full replacement, so adding one line to a
large document meant resending the whole document — expensive enough
that edits were being skipped rather than risk silently truncating
shared team documents.

memory.patch replaces one exact occurrence of old_string. An absent or
ambiguous match is an error, never a silent no-op and never an
arbitrary pick; that refusal is what makes the operation safe to hand
to an agent. The semantics live in lib/memory-patch.ts as a pure
function, free of DB and auth, so both surfaces share them.

Shared mutation layer
---------------------
The MCP tools and the Web UI Server Actions each reimplemented
authorize -> mutate -> re-embed -> CAS -> audit, and had drifted. Both
now route through lib/memory-mutations.ts.

BEHAVIOUR CHANGE: memory.delete over MCP skipped the project ACL
whenever the caller authored the row, so a memory written while a share
was rw stayed deletable by its author after an owner downgraded that
share to ro. memory.update and the whole Web UI always checked.
Authoring a row now grants no standing write privilege on any path.

The one deliberate difference between the surfaces is injected as a
ProjectResolver: MCP refuses an unknown project key so an agent cannot
spawn near-miss projects off a typo, while the Web UI creates one
because a person typing a name into a form means to.

Tests and lint
--------------
Adds vitest. The integration tests run against a real Postgres rather
than a mocked DB. The embedder sidecar is the only stub and it is
deterministic per-text, so re-embedding is verified by asserting the
stored vector actually changed rather than that a mock was called. One
test pins that content_tsv is a generated column and therefore cannot
rot after a patch — only the embedding needs an explicit recompute.

pnpm lint previously dropped into an interactive `next lint` setup
prompt and exited 1; ESLint had never been configured here. Replaced
with the ESLint CLI and a flat config bridging eslint-config-next
through FlatCompat. Clean at --max-warnings=0.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

apps/web/app/(authed)/dashboard/page.tsx

@@ -5,7 +5,7 @@ import { db } from "@/lib/db/client";
 import { memories, projects, projectShares } from "@/lib/db/schema";
 import { getUserGroupNames, readableProjectIds } from "@/lib/access";
 import { Container, PageHeader } from "@/app/_components/ui/container";
-import { Card, CardBody, CardHeader } from "@/app/_components/ui/card";
+import { Card, CardBody } from "@/app/_components/ui/card";
 import { Badge } from "@/app/_components/ui/badge";
 import { Button } from "@/app/_components/ui/button";
 import { EmptyState } from "@/app/_components/ui/empty-state";

apps/web/app/(authed)/projects/[key]/activity/page.tsx

@@ -6,7 +6,7 @@ import { db, pg } from "@/lib/db/client";
 import { projects, users } from "@/lib/db/schema";
 import { getProjectAccess, getUserGroupNames, readableProjectIds } from "@/lib/access";
 import { Container, PageHeader } from "@/app/_components/ui/container";
-import { Card, CardBody } from "@/app/_components/ui/card";
+import { Card } from "@/app/_components/ui/card";
 import { Badge } from "@/app/_components/ui/badge";
 import { Button } from "@/app/_components/ui/button";
 import { EmptyState } from "@/app/_components/ui/empty-state";

apps/web/app/(authed)/settings/tokens/page.tsx

@@ -1,5 +1,5 @@
 import { revalidatePath } from "next/cache";
-import { and, asc, desc, eq, isNull } from "drizzle-orm";
+import { and, asc, desc, eq } from "drizzle-orm";
 import { auth } from "@/auth";
 import { env } from "@/lib/env";
 import { db } from "@/lib/db/client";