chore: Release 0.4.4 - AGPL license migration

- Update version from 0.4.3 to 0.4.4 across all packages
- Migrate license from Apache-2.0 to AGPL-3.0-or-later
- Add SPDX-License-Identifier to all 316 Rust source files
- Update copyright year to 2026 and full name (Sushanth Reddy Vanagala)
- Add comprehensive license section to README.md
- Create NOTICE file with copyright and acknowledgments
- Update Cargo.toml license field to AGPL-3.0-or-later
- All tests passing (660 tests)

Merge pull request #19 from sochdb/release/0.4.3

feat(queue): add comprehensive queue optimization with atomic claim p…

Merge pull request #18 from sochdb/release/0.4.2

Fix SIMD function name mismatches in HNSW implementation

Fixed the windows build issue.

Release v0.4.0 - Version bump for crates.io publication

- Updated all package versions from 0.3.x to 0.4.0
- Updated workspace version to 0.4.0
- Updated Python package version to 0.4.0
- Updated README with v0.4.0 release notes
- Added comprehensive release notes documenting the rename
- Updated benchmark version references
- All builds and tests passing
- Ready for crates.io publication

Merge pull request #13 from toondb/release/0.3.6

feat: Add FFI bindings for native collection search

docs: Add comprehensive v0.3.5 documentation

- Add 'What's New in v0.3.5' section to README with sync-first architecture overview

- Update 'Database fundamentals' section with AST-based SQL executor and idempotent DDL

- Create docs/RELEASE_NOTES_0.3.5.md with complete release notes

- Create docs/ARCHITECTURE_SYNC_FIRST.md with architecture deep dive

Merge pull request #11 from toondb/release/0.3.4

Release/0.3.4

Merge pull request #10 from toondb/release/0.3.3

Release v0.3.3: Graph Overlay, Context Query enhancements, Policy Hoo…

Merge pull request #9 from toondb/release/0.3.1

Release v0.3.1: Add optional usage analytics with privacy controls