Refactor run.sh for improved agent version handling

feat: show bot version after selection; fix No valid version error msg

Fix: BotDefinition has no Status field — remove from query and display

Fix: fall back to querying all bots when Active/Draft filter returns none

Fix: saved credentials skipped due to Windows CR and invalid SOQL status

fix: show latency in seconds instead of milliseconds

feat: 3 improvements — agent status filter, saved credentials fallback, latency display

fix: filter agent list to active agents only

feat: add per-topic mutable context variables in test generation

fix: preserve GEN_LLM_PROVIDER when restored by --run lastrun

docs: add OAuth callback URL to Agent API setup steps

docs: rewrite README with full feature documentation

Initial release: AGITEST Agentforce Testing Custom CLI