refactor: split supervisor into infra + per-project, make poll scripts config-driven

Supervisor split (#26):
- Layer 1 (infra): P0 memory, P1 disk, P4 housekeeping — runs once, project-agnostic
- Layer 2 (per-project): P2 CI/dev-agent, P3 PRs/deps — iterates projects/*.toml
- Adding a new project requires only a new TOML file, no code changes

Poll scripts accept project TOML arg (#27):
- dev-poll.sh, review-poll.sh, gardener-poll.sh accept optional project TOML as $1
- env.sh loads PROJECT_TOML if set, overriding .env defaults
- Cron: `dev-poll.sh projects/versi.toml` targets that project

New files:
- lib/load-project.sh: TOML to env var loader (Python tomllib)
- projects/versi.toml: current project config extracted from .env

Backwards compatible: scripts without a TOML arg fall back to .env config.

Closes #26, Closes #27

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

projects/versi.toml

@@ -0,0 +1,21 @@
+# projects/versi.toml — Project config for johba/versi
+#
+# This file defines project-specific settings for disinto agents.
+# Drop a new TOML file here to add another project — no code changes needed.
+
+name            = "versi"
+repo            = "johba/versi"
+repo_root       = "/home/admin/versi"
+primary_branch  = "main"
+
+[ci]
+woodpecker_repo_id = 3
+stale_minutes      = 60
+
+[services]
+containers = []
+
+[monitoring]
+check_prs            = true
+check_dev_agent      = true
+check_pipeline_stall = true