Remove unused devDependency `@types/lowdb` (superseded by lowdb's own bundled types)

[pinecone-groundskeeper]

Problem

explorer/package.json lists @types/lowdb: "^1.0.15" as a devDependency
(line 19), alongside the runtime dependency lowdb: "^7.0.1" (line 26).

@types/lowdb@1.0.15 provides type definitions for lowdb's v1 API (the
low(adapter) factory function and old adapter shapes). The pinned lowdb@7
no longer matches that API — it ships its own bundled TypeScript types
directly in the package ("types": "./lib" plus a typesVersions map for the
./node and ./browser subpaths, per node_modules/lowdb/package.json), which
is what the actual imports in explorer/src/app/api/opinion/route.ts
(LowSync, JSONFile, JSONFileSync from 'lowdb' / 'lowdb/node') resolve
against. @types/lowdb is therefore never consulted by the TypeScript compiler
for these imports — TS resolves types straight from lowdb's own bundled
declarations.

Confirmed nothing in the codebase imports from @types/lowdb directly (it
isn't importable as a module anyway — @types/* packages only supply ambient
type declarations): a repo-wide search only turns up the dependency
declaration itself in explorer/package.json and its lockfile entries in
explorer/pnpm-lock.yaml.

Acceptance criteria

• @types/lowdb is removed from explorer/package.json devDependencies.
• explorer/pnpm-lock.yaml is regenerated (via pnpm install) so the stale
  entry is dropped.
• pnpm run build, pnpm run lint, and pnpm run test in explorer/ still
  succeed, confirming no code actually depended on @types/lowdb's type
  declarations.

Scope

Remove only the unused @types/lowdb devDependency and regenerate the
lockfile. Out of scope: any change to the lowdb runtime dependency itself or
to the code that uses it.

Generated by GitHub Maintenance Audit · sonnet50 · 80.4 AIC · ⌖ 6.1 AIC · ⊞ 7.9K · ◷