chore: remove dead env vars, requirements files, and yarn.lock

- Remove 10 unused env vars from .env.example (APP_TOKEN, AUTH_BASE_URL,
  ENDPOINT, MEETUP_EMAIL, MEETUP_PASS, POETRY, PY_VER, RUN_TIME,
  TIME_DELTA, URLNAME)
- Remove requirements.txt and requirements-dev.txt (project uses uv
  with pyproject.toml)
- Remove yarn.lock (no package.json; leftover from commitizen)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: pythoninthegrass

.env.example

@@ -1,7 +1,4 @@
 ALGORITHM=HS256
-DB_PATH=/data/meetup_bot.db
-APP_TOKEN=xapp-apptoken
-AUTH_BASE_URL=https://secure.meetup.com/oauth2/authorize
 BOT_USER_TOKEN=xoxb-botusertoken
 CACHE_FN=/tmp/meetup_query
 CHANNEL=okc-metro
@@ -11,34 +8,27 @@ CLIENT_SECRET=secretsecuresuper
 CSV_FN=/tmp/output.csv
 DAYS=7
 DB_PASS=anothercredgoeshere
+DB_PATH=/data/meetup_bot.db
 DB_USER=someuser
-ENDPOINT=emoji.list
 HOST=localhost
 JSON_FN=/tmp/output.json
 JWT_LIFE_SPAN=120
-MEETUP_EMAIL=username@acme.com
-MEETUP_PASS=supersecurepassword
-POETRY=1.7.1
 PORT=3000
 PRIV_KEY_B64=base64_encoded_private_pem_key
 PUB_KEY_B64=base64_encoded_public_pem_key
-PY_VER=3.11.6
 REDIRECT_URI=https://acme.com
-REGISTRY_URL=docker.io
 REGISTRY_PASS=containerregistrytoken
-RUN_TIME=1400
+REGISTRY_URL=docker.io
 SECRET_KEY=secretmeetinginthebasementofmybrain
 SELF_ID=techlahomauserid
 SERVICE=meetup-bot
 SIGNING_KEY_ID=activejwtkeyid
 SIGNING_SECRET=33characterstringthatImm1micking!
 SLACK_WEBHOOK=incomingwebhook
-TIME_DELTA=1
 TOKEN_EXPIRE=30
 TOKEN_URL="https://secure.meetup.com/oauth2/access"
 TTL=3600
 TZ=America/Chicago
-URLNAME=Techlahoma-Foundation
 USER_NAME=containerregistryusername
 USER_TOKEN=xoxp-usertoken