fix: CRLF/BOM line endings + restart policies + gitattributes

- poller/docker-entrypoint.sh: convert from CRLF+BOM to LF (UTF-8 no BOM)
  Windows saved the file with a UTF-8 BOM which made the Linux kernel
  reject the shebang with 'exec format error', crashing the poller.

- infrastructure/openbao/init.sh: same CRLF -> LF fix

- poller/Dockerfile: add sed to strip CRLF and BOM at image build time
  as a defensive measure for future Windows edits

- docker-compose.override.yml: add 'restart: on-failure' to api and poller
  so they recover from the postgres startup race (TimescaleDB restarts
  postgres after initdb, briefly causing connection refused on first boot)

- .gitattributes: enforce LF for all text/script/code files so git
  normalises line endings on checkout and prevents this class of bug

docker-compose.override.yml

@@ -7,6 +7,7 @@ services:
       context: .
       dockerfile: infrastructure/docker/Dockerfile.api
     container_name: tod_api
+    restart: on-failure
     ports:
       - "8001:8000"
     env_file: .env
@@ -66,6 +67,7 @@ services:
       context: ./poller
       dockerfile: ./Dockerfile
     container_name: tod_poller
+    restart: on-failure
     env_file: .env
     environment:
       ENVIRONMENT: dev