refactor: make all scripts multi-project via env vars

Replace hardcoded harb references across the entire codebase:
- HARB_REPO_ROOT → PROJECT_REPO_ROOT (with deprecated alias)
- Derive PROJECT_NAME from CODEBERG_REPO slug
- Add PRIMARY_BRANCH (master/main), WOODPECKER_REPO_ID env vars
- Parameterize worktree prefixes, docker container names, branch refs
- Genericize agent prompts (gardener, factory supervisor)
- Update best-practices docs to use $-vars, prefix harb lessons

All project-specific values now flow from .env → lib/env.sh → scripts.
Backward-compatible: existing harb setups work without .env changes.

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

.env.example

@@ -2,17 +2,23 @@
 # Copy to .env and fill in your values.
 # NEVER commit .env to the repo.
 
+# ── Target project ────────────────────────────────────────────────────────
+CODEBERG_REPO=johba/yourproject            # org/repo slug on Codeberg
+PROJECT_REPO_ROOT=/home/you/yourproject    # local clone of the target repo
+PRIMARY_BRANCH=main                        # main or master
+# PROJECT_NAME=yourproject                 # optional — auto-derived from CODEBERG_REPO
+
+# ── Auth tokens ───────────────────────────────────────────────────────────
 # Codeberg API token (read from ~/.netrc by default, override here if needed)
 # CODEBERG_TOKEN=
 
 # Codeberg review bot token (separate account for formal reviews)
 REVIEW_BOT_TOKEN=
 
-# Woodpecker CI API token
+# ── Woodpecker CI ─────────────────────────────────────────────────────────
 WOODPECKER_TOKEN=
-
-# Woodpecker CI server URL
 WOODPECKER_SERVER=http://localhost:8000
+WOODPECKER_REPO_ID=2                       # numeric repo ID in Woodpecker DB
 
 # Woodpecker Postgres (for direct DB queries)
 WOODPECKER_DB_PASSWORD=
@@ -20,12 +26,5 @@ WOODPECKER_DB_USER=woodpecker
 WOODPECKER_DB_HOST=127.0.0.1
 WOODPECKER_DB_NAME=woodpecker
 
-# Target Codeberg repo
-CODEBERG_REPO=johba/harb
-CODEBERG_API=https://codeberg.org/api/v1/repos/johba/harb
-
-# Harb repo local path
-HARB_REPO_ROOT=/home/debian/harb
-
-# Claude CLI timeout (seconds)
-CLAUDE_TIMEOUT=7200
+# ── Tuning ────────────────────────────────────────────────────────────────
+CLAUDE_TIMEOUT=7200                        # max seconds per Claude invocation