docs: update README and website for v0.3.0 release

README changes:
- Rewrite intro to focus on context provider role
- Document new tools (dev_refs, dev_map)
- Document dev_plan refactor to context assembly
- Add example output for dev_map
- Simplify structure and reduce length
- Add version history section

Website changes:
- Add dev_refs tool documentation
- Add dev_map tool documentation
- Update dev_plan docs for context assembly
- Update tools overview with new tools
- Add 'New in v0.3.0' section

Changeset:
- Create changeset for v0.3.0 Context Quality release

Author: prosdev

.changeset/context-quality-v03.md

@@ -0,0 +1,51 @@
+---
+"@lytics/dev-agent": minor
+"@lytics/dev-agent-core": minor
+"@lytics/dev-agent-mcp": minor
+"@lytics/dev-agent-subagents": minor
+---
+
+feat: Context Quality release (v0.3.0)
+
+This release significantly enhances dev-agent's ability to provide rich, actionable context to AI assistants.
+
+## New Tools
+
+### `dev_refs` - Relationship Queries
+Query code relationships to understand what calls what:
+- Find all callers of a function
+- Find all callees (what a function calls)
+- Includes file paths, line numbers, and snippets
+
+### `dev_map` - Codebase Overview
+Get a high-level view of repository structure:
+- Directory tree with component counts
+- **Hot Paths**: Most referenced files in the codebase
+- **Smart Depth**: Adaptive expansion based on information density
+- **Signatures**: Function/class signatures in export listings
+- Configurable depth and focus directory
+
+## Enhanced Tools
+
+### `dev_plan` - Context Assembler (Breaking Change)
+Completely refactored from heuristic task breakdown to context assembly:
+- Returns rich context package instead of task lists
+- Includes issue details with comments
+- Includes relevant code snippets from semantic search
+- Includes detected codebase patterns
+- Let LLMs do the reasoning with better data
+
+**Migration:** The old task breakdown output is removed. The new output provides strictly more information for LLMs to create their own plans.
+
+### `dev_search` - Richer Results (from v0.2.0)
+- Code snippets included in results
+- Import statements for context
+- Caller/callee hints
+- Progressive disclosure based on token budget
+
+## Philosophy
+
+This release embraces the principle: **Provide structured data, let LLMs reason.**
+
+Instead of trying to be smart with heuristics, dev-agent now focuses on assembling comprehensive context that AI assistants can use effectively.
+