feat(examples): bump pins to @subsquid/ponder@0.16.8-sqd.1

[dzhelezov]

What

Bump all three example pins from 0.16.6-sqd.2 to @subsquid/ponder@0.16.8-sqd.1 — the version just published to npm as the latest dist-tag. Each example is bumped in both places, kept in sync so the harness's assertCommittedPin (package.json dep === e2e.json pin) holds:

• examples/euler-subgraph — package.json dep + e2e.json pin
• examples/euler-multichain — package.json dep + e2e.json pin
• examples/uniswap-portal — package.json dep + e2e.json pin

Pin bump only — no code, config, or graphql-assertion changes.

Validation — published package proven end-to-end via the e2e freshness gate

Ran scripts/examples-e2e.mjs per-example (the way CI runs it, one example per invocation), installing the published 0.16.8-sqd.1 from npm and indexing mainnet keyless via the free public SQD Portal:

example	--check-pins	--verify-docs	e2e	observed graphql counts
euler-subgraph	PASS	PASS	PASS	vaults=39, deposits=504, withdraws=163, borrows=185, repays=35
uniswap-portal	PASS	PASS	PASS	swaps=848, routerCalls=1676, blockTicks=3, accountTxs=1871

--check-pins (require pin === npm latest) passes for all three now that the pins equal 0.16.8-sqd.1. Both single-mainnet-chain examples index green on the published package with rpc_fallback=0 (history served entirely by the Portal), and all graphql assertions pass with comfortable margin over their min thresholds.

"Released and visible" — default-level Portal provenance (issue #115)

Captured from the euler-subgraph run on the published package at default log level, confirming the Portal path is active and serves the history end-to-end:

INFO  Portal backfill active for mainnet: https://portal.sqd.dev/datasets/ethereum-mainnet
INFO  Portal mainnet progress: blocks_streamed=26 mb_streamed=0.75 blocks_per_s=1.3 discChunks=2 scanned=256265
INFO  Portal mainnet progress: blocks_streamed=380 mb_streamed=4.50 blocks_per_s=9.5 discChunks=3 scanned=301265
INFO  Portal mainnet complete: blocks=666 logs=1826 txs=672 receipts=0 mb_streamed=6.95 elapsed=56.1s avg_blocks_per_s=11.9 rpc_fallback=0 — served entirely by the SQD Portal (0 JSON-RPC for history)

Note — euler-multichain e2e in a keyless environment (pre-existing, version-neutral)

Run keyless, euler-multichain does not complete the gate: the harness reports metrics file not found: ...portal-metrics.8453. This is not introduced by this bump — the identical failure reproduces on the previous pin 0.16.6-sqd.2. Its base/arbitrum demo windows stream blocks=0 (no factory deployments in the sampled window), and the per-chain metrics file is only written on the block-insertion path, so a 0-block chain produces no metrics file for the harness to read. In CI these chains are exercised with their configured RPC endpoints; this note is about the keyless path only. Out of scope for this surgical pin bump; flagged for a separate follow-up.

Gates

• npx @biomejs/biome@2.5.2 check . — 0 errors (pre-existing warnings only; the 6 changed JSON files check clean).
• Secret scan of the diff — clean.