feat(indexer): vendor squid-subsquid-network into the monorepo

[belopash]

Summary

Merges the subsquid/squid-subsquid-network indexer into this monorepo via git subtree. After this PR the four production squids (workers, gateways, token, vestings) plus their shared package live as first-class workspace members under packages/, and all workspace packages — app and indexer — share the @sqd/* npm scope.

Why

• Single source of truth — address-book / ABI / schema changes happen in one PR, not two.
• Drops the build-time tools/devnet/patches/ step (follow-up PR after the companion devnet PR lands).
• Makes type-level coupling between client/server and the indexer's GraphQL schema tractable in the future.

Layout after this PR

packages/
├── client/             # @sqd/client          (renamed from @subsquid/client)
├── common/             # @sqd/common          (renamed from @subsquid/common)
├── server/             # @sqd/server          (renamed from @subsquid/server)
├── indexer-common/     # @sqd/indexer-common  (renamed from @sqd/shared, vendored)
├── indexer-workers/    # @sqd/workers         (vendored)
├── indexer-gateways/   # @sqd/gateways        (vendored)
├── indexer-token/      # @sqd/token           (vendored)
└── indexer-vestings/   # @sqd/vestings        (vendored)
indexer/                # vendored squid tooling: ABIs, manifests, scripts, plans, biome.json, tsconfig.base.json

Key decisions

• git subtree add, no --squash. Preserves upstream history. Future bumps: git subtree pull --prefix=indexer https://github.com/subsquid/squid-subsquid-network.git master (then re-flatten + re-rename).
• Flat layout under packages/. Indexer packages live alongside app packages so a single workspace glob (packages/*) covers everything.
• indexer-common rename. The vendored @sqd/shared is renamed to @sqd/indexer-common to make the role obvious next to the existing app-side @sqd/common. There IS conceptual overlap between the two (both ship contract ABIs + address books for the same contracts), but the shape differs — wagmi-tuple vs. @subsquid/evm-codec event/fun factories — so deduplication needs a real API unification. Tracked as a follow-up; deliberately out of scope of this PR.
• Scope unification. @subsquid/{client,common,server} → @sqd/{client,common,server}. @subsquid/* references in source/imports now refer exclusively to upstream npm packages (@subsquid/batch-processor, @subsquid/typeorm-store, etc.).

Toolchain coexistence

	App	Indexer
TypeScript	5.9	5.9 (verified — indexer builds clean against 5.9; decorator metadata works)
Vitest	4.x	2.x (per-package, no conflict)
Biome	2.3	1.9 (root biome ignores indexer/ and packages/indexer-*; indexer keeps its own indexer/biome.json)
Module type	ESM	CJS (per-package; rolldown bundles to CJS)
Output dir	build/, dist/	lib/ (added to root .gitignore)

Verification

• pnpm install succeeds; lockfile committed.
• pnpm build — full turbo graph (8 packages) green: client / common / server / 5× indexer-*.
• pnpm build:indexer — runs rolldown -c && tsc -p tsconfig.model.json for each indexer-* package.
• pnpm lint — green (3 pre-existing client warnings, unrelated).
• pnpm tsc — green for @sqd/client and @sqd/server.
• pnpm --filter @sqd/workers test — 6 vitest tests pass under indexer-bundled vitest 2.

Out of scope (explicit non-goals)

• ABI deduplication between @sqd/common and @sqd/indexer-common — needs API unification first.
• ESM migration of indexer packages.
• Unifying biome / vitest / typescript major versions across both stacks.
• CI to build/deploy the indexer from this repo. The indexer is deployed via SQD's own pipeline; this repo only vendors source.
• The companion devnet-stack PR (cursor/mock-wallet-d5dd) — once both land, a small follow-up drops external/squid-subsquid-network submodule + tools/devnet/patches/ + the Dockerfile copy step.

Follow-ups

1. Drop the indexer submodule + devnet build-time patch (after both PRs land).
2. ABI / address-book deduplication between @sqd/common and @sqd/indexer-common.
3. (Optional) CI for indexer builds in this repo.