refactor(cli): change from env var injection to direct prompt concatenation

- Replace $PROTO/$TMPL environment variable injection with systemRules/roles direct concatenation
- Append rules to END of prompt instead of prepending
- Change prompt field name from RULES to CONSTRAINTS in all prompts
- Default to universal-rigorous-style template when --rule not specified
- Update all .claude documentation, agents, commands, and skills
- Add streaming_content type support for Gemini delta messages

Breaking: Prompts now use CONSTRAINTS field instead of RULES

ccw/src/tools/cli-executor-core.ts

@@ -1149,7 +1149,7 @@ async function executeCliTool(
         duration_ms: duration,
         output: newTurnOutput,
         parsedOutput: flattenOutputUnits(allOutputUnits, {
-          excludeTypes: ['stderr', 'progress', 'metadata', 'system', 'tool_call']
+          excludeTypes: ['stderr', 'progress', 'metadata', 'system', 'tool_call', 'thought']
         })
       };