Merge origin/main into staging — absorb unsynced release (v3.12.0, #627) before promotion

main carried an unsynced release (#627 Path B /api/notify + erc20_overrides, plus
version bumps v3.11.0 / v3.12.0) that never came back to staging, so the
staging→main PR (#636) conflicted. Back-merge main into staging to realign.

Conflict resolutions:
- summarizer_deterministic.go, summarizer_run_node_test.go: kept DELETED — staging
  removed the deterministic summarizer in #628; main only modified them.
- vm_runner_rest.go, summarizer_context_memory.go: kept STAGING's Path-B-only
  notify rewrite (#628/#629) — it supersedes main's older #627 notify code
  (removed the duplicate BuildNotifyPayload, legacy telegram branch, summaryForClient).
- run_node_immediately_rpc_test.go: kept staging's explicit per-node ChainId (G5 strict).

Net effect on staging: brings in main's version bump (3.10.4 → 3.12.0); everything
else from #627 was already present (#624/#626) or superseded. Build + affected
suites green.

Author: Chris Li

version/version.go

@@ -10,7 +10,7 @@ var (
 	// Keep `semver` here roughly in sync with the latest release tag as a
 	// safety net — if a build slips through without ldflags, /health will
 	// still report something plausible rather than ancient history.
-	semver   = "3.10.4"
+	semver   = "3.12.0"
 	revision = "unknown"
 )
 
@@ -22,4 +22,4 @@ func Get() string {
 // GetRevision returns the revision
 func GetRevision() string {
 	return revision
-}
+}