fix(agents): the claude projects root follows CLAUDE_CONFIG_DIR too (Issue #31, review)

stop resolves the uuid before it purges, through lib.sh's exported
CLAUDE_PROJECT_DIR and DiscoveryContext.claude_dir, both of which defaulted
to $HOME/.claude/projects. With CLAUDE_CONFIG_DIR alone the transcript under
<cfg>/projects was not found, so stop removed the row and purged nothing.
Both defaults are now ${CLAUDE_CONFIG_DIR:-<home>/.claude}/projects; an
explicit CLAUDE_PROJECT_DIR still wins.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.agents/skills/lib_py/agents/base.py

@@ -156,7 +156,9 @@ class DiscoveryContext:
         self.workspace = workspace
         self.agent_name = agent_name
         self.home_dir = resolve_home(home_dir)
-        self.claude_dir = claude_dir or os.environ.get("CLAUDE_PROJECT_DIR", f"{self.home_dir}/.claude/projects")
+        # projects/ lives under claude's config root, which CLAUDE_CONFIG_DIR moves.
+        config_root = os.environ.get("CLAUDE_CONFIG_DIR") or f"{self.home_dir}/.claude"
+        self.claude_dir = claude_dir or os.environ.get("CLAUDE_PROJECT_DIR", f"{config_root}/projects")
         self.epoch = epoch
         self.row = row or {}
         self.mode = mode