refactor: improve DID generation and error handling

- Convert did_generator.sh to output clean JSON
- Add structured error reporting with stages
- Improve debug logging with DEBUG flag
- Better error handling in run-deeplink-tests.sh
- Add detailed debug tracing
- Fix JSON parsing and validation
- Add visual feedback for generated DIDs
- Use printf instead of echo for consistent output
- Remove stderr mixing with stdout
- Add proper exit status handling

This refactors the DID generation process to be more reliable
and maintainable by using structured JSON output and proper
error handling throughout the pipeline.

test-scripts/check-did.sh

@@ -3,7 +3,7 @@
 # Usage: ./check-did.sh [did]
 # If no DID provided, lists all visible DIDs
 
-API_URL=${ENDORSER_API_URL:-"https://test-api.endorser.ch/api/v2/claim"}
+API_URL=${ENDORSER_API_URL:-"https://test-api.endorser.ch/api/whichDidsICanSee"}
 ADMIN_DID="did:ethr:0x0000694B58C2cC69658993A90D3840C560f2F51F"
 ADMIN_KEY="2b6472c026ec2aa2c4235c994a63868fc9212d18b58f6cbfe861b52e71330f5b"