refactor(prp-core): make docs-impact-agent and code-simplifier advisory-only

fix(prp-core): auto-detect base branch instead of hardcoding main

feat(prp-core): add /prp-research-team command for agent teams research planning

fix(prp-core): wrap hooks.json in required top-level hooks key

chore(prp-core): bump plugin version to 2.3.0

feat(prp-core): use specialized agents in commands, add codebase-question and gpui-researcher

fix: move description field before owner in marketplace.json

fix: remove invalid capabilities field from .claude/agents

fix(prp-core): add required frontmatter fields to all agents

fix(prp-core): correct hooks.json structure for plugin spec

fix(prp-core): simplify plugin.json to essential fields only

fix(prp-core): remove agents field - auto-discovered by convention

Revert "fix(prp-core): remove agents field - not supported in current schema"

fix(prp-core): remove agents field - not supported in current schema

fix(prp-core): use valid plugin agent frontmatter schema