chore: universal workspace ignore in .gitignore and .dockerignore

- .gitignore: **/workspace/ (was agentexample/**/workspace/ only)
  Covers both agentexample/ and future PaaS agent dirs.
  Allows .gitkeep to preserve empty workspace dirs in repo.
- .dockerignore: **/workspace/ — run data never goes into image

Agent directory structure principle:
  {agent_dir}/          ← config, prompts, knowledge (versioned)
  {agent_dir}/workspace/  ← run data (local, never tracked)

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

.dockerignore

@@ -0,0 +1,17 @@
+.venv
+__pycache__
+*.pyc
+.git
+agentexample
+docs
+tests
+experiments
+charts
+*.db
+*.md
+!agentpaas/**
+.claude
+agent-lint-action
+
+# Agent workspace — run data never goes into image
+**/workspace/

.gitignore

@@ -161,6 +161,9 @@ __pycache__/
 patents/patent-01-lint/node_modules/
 
 # ==============================
-# Agent workspace (local data, not tracked)
+# Agent workspace — run data, not tracked
+# Each run creates workspace/run_YYYYMMDD_HHMMSS/ with intermediate
+# and final artifacts. These are local execution data, never committed.
 # ==============================
-agentexample/**/workspace/
+**/workspace/
+!**/workspace/.gitkeep