feat: add prompt library (#77)

* refactor: extract shared markdown builders for rules generation strategies (#73)

Extract common scaffolding from Single and Multi file strategies into reusable builders module. This reduces code duplication and ensures consistent formatting across both strategies.

Key changes:
- Created markdown-builders module with shared utilities
- Extracted project header, empty state, and library section rendering
- Unified iteration logic over layer/stack/library structure
- Simplified both strategies to use shared builders

Benefits:
- Guarantees consistent formatting across strategies
- Reduces effort when adding new strategies
- Single source of truth for markdown generation logic
- Easier maintenance and testing

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-authored-by: Claude <noreply@anthropic.com>

* refactor: centralize keyboard activation handling (#71)

* refactor: centralize keyboard activation handling

* test: add coverage for useKeyboardActivation hook

* docs: add prompt-manager plans and custom prompts

* docs: updates to reflect feedback

* docs: create prd

* feat: implement phase 1 (flags and access)

* feat: implement phase 2 (organizations)

* fix: remove typo from impl plan documents

* feat: implement phase 3 (prompt collections and admin apis)

* refactor: rename collections to differentiate between prompts and collections

* feat: implement phase 4 (member api and ui)

* feat: implement phase 5 (admin ui)

* feat: implement phase 7 (localization)

* feat: add UI adjustments

* fix: handle localization in search

* feat: implement link to prompt

* feat: implement invite links

* feat: apply RLS to protect access

* refactor: simplify test mocks

* refactor: rename prompt manager to prompt library

* chore: update migrations order and consolidate rls

* chore: cleanup docs

* feat: enable prompt library on prod

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Co-authored-by: Claude <noreply@anthropic.com>

Author: mkczarkowski