fix: separate poll_interval from compact_pct in local-model agent TOML config

--poll-interval was incorrectly written as compact_pct in the project TOML,
misconfiguring CLAUDE_AUTOCOMPACT_PCT_OVERRIDE instead of polling behavior.
Now compact_pct is hardcoded to 60 (the correct default) and poll_interval
is a separate TOML field emitted as POLL_INTERVAL in the compose service.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

projects/disinto.toml.example

@@ -34,6 +34,7 @@ check_pipeline_stall = false
 #   roles = ["dev"]
 #   forge_user = "dev-qwen"
 #   compact_pct = 60
+#   poll_interval = 60
 
 # [mirrors]
 # github   = "git@github.com:johba/disinto.git"