Show project tech tags on project cards

[akmhatey-ai]

Summary

• Render each project's existing tech_stack on the /projects cards.
• Cap the visible tags at four items so cards stay compact.
• Add a LiveView test covering project tech tag rendering.

Closes #197.

Validation

• mix format --check-formatted lib/algora_web/live/orgs_live.ex test/algora_web/live/orgs_live_test.exs
• MIX_ENV=test mix test test/algora_web/live/orgs_live_test.exs in WSL with a temporary local Postgres instance: 1 test, 0 failures
• git diff --check
• gitleaks detect --pipe --redact --verbose --no-color

Notes

• I did not run the full test suite.

[CLAassistant]

All committers have signed the CLA.