feat: automate type generation with append-only version log

Replace hand-maintained src/types/ with auto-generated types from
Subsquid typegen, seeded from all TFChain networks (devnet, qanet,
testnet, mainnet). JSONL sorted by specVersion so typegen assigns
the lowest version label for each unique event hash.

Infrastructure:
- Add scripts/merge-versions.js: append-only JSONL merger, sorted output
- Add scripts/seed-versions.sh: multi-network metadata discovery
  (order: devnet -> qanet -> testnet -> mainnet)
- Seed typegen/tfchainVersions.jsonl with 93 specVersions from all networks
- Update typegen/typegen.json: output directly to src/types/, add 3 events
  to config that were used by processor but missing from typegen config
  (FarmCertificationSet, NodeCertificationSet, FarmingPolicyUpdated)
- Add Makefile targets: typegen, typegen-seed, typegen-add
- Rewrite docs/typeChanges.md with automated workflow, deployment order,
  resync guidance, and notes on typesBundle.json being frozen

Type generation:
- Regenerate src/types/ from chain metadata (correct hashes)
- Remove src/typesDevelopment/ (no longer needed)
- Remove src/types/context.ts (unused)

Mapping renames (all verified: identical hashes and type structures):
- V49 -> V9: FarmDeleted, FarmPayoutV2, NodeDeleted, NodeUptimeReported,
  TwinDeleted, TwinStored, TwinUpdated, PricingPolicyStored
- V49 -> V19: NodeContractCanceled, NameContractCanceled, PriceStored
- V49 -> V12: NodePublicConfigStored
- V101 -> V63: FarmStored, FarmUpdated, NodeStored, NodeUpdated
- V122 -> V123: All ServiceContract events
- V124 -> V125: TwinStored, TwinUpdated
- V134 -> V140: NodeExtraFeeSet
- Removed dead branches with phantom hashes from wrong field ordering
  (FarmStored/Updated V63, NodeStored/Updated V63, TwinStored/Updated V49)
- Removed unused v63 import from farms.ts

Author: sameh-farouk

Makefile

@@ -1,4 +1,4 @@
-.PHONY: version-bump
+.PHONY: version-bump typegen typegen-seed typegen-add
 
 # usage: > type=patch make version-bump
 # usage: > type=minor make version-bump
@@ -20,3 +20,21 @@ version-bump:
 	else \
 		echo "Invalid version type. Please use patch, minor, or major."; \
 	fi
+
+# Regenerate src/types/ from accumulated specVersions in tfchainVersions.jsonl
+typegen:
+	npx squid-substrate-typegen typegen/typegen.json
+
+# Discover all specVersions from all TFChain networks (mainnet, testnet, qanet, devnet)
+typegen-seed:
+	./scripts/seed-versions.sh
+
+# Add new specVersion from a chain endpoint and regenerate types
+# Usage: make typegen-add
+# Usage: WS_URL=wss://tfchain.test.grid.tf make typegen-add
+typegen-add:
+	npx squid-substrate-metadata-explorer \
+		--chain $${WS_URL:-ws://localhost:9944} \
+		--out /tmp/new_versions.jsonl
+	node scripts/merge-versions.js typegen/tfchainVersions.jsonl /tmp/new_versions.jsonl
+	npx squid-substrate-typegen typegen/typegen.json