v0.3.0 — TUI Overhaul

• release: v0.3.0 — TUI overhaul with Unicode art, brand colors, and polished navigation (ac74607)
• docs: update TUI documentation for v0.3.0 release (e9cfaa2)
• style: remove blank line between menu title and options (68b7c43)
• Revert "style: remove extra blank line before grouped menus" (2cc8a0c)
• style: remove extra blank line before grouped menus (9c431f9)
• style: use exact ORAS brand colors for banner letters (8820970)
• style: align menu options by grouping all choices consistently (8fdb61e)
• style: match TUI banner colors to ORAS brand purple palette (89f7577)
• refactor: replace FigletText banner with Unicode block art and color gradient (29c7cf4)
• fix: make menu separators non-selectable and show all registries (0a1ccf9)
• feat: add visual separator before Quit/Back in TUI menus (c0ebcea)
• feat: enable cyclic wrap-around navigation in all TUI menus (2eed105)
• refactor: replace ASCII indicators with Unicode symbols in TUI (7193641)
• refactor: convert artifact group to sub-menu in TUI dashboard (8dc6f07)
• Add critical unit tests for Tier 1 and Tier 2 targets (e9dc515)
• refactor: extract shared utilities, remove dead code, standardize patterns (82f1f5c)
• Fix DI patterns and helper timeout (d930ed9)
• Propagate cancellation tokens in CLI commands (67809f7)
• Refactor TUI artifact actions (022467f)
• Fix AOT-safe output formatting (4c362d7)
• chore: remove unused .copilot example config (008b79a)
• feat: group artifact operations in TUI dashboard menu (115e7a1)
• fix: use source-generated JSON for AOT-compatible credential serialization (6500814)
• [Scribe] Log orchestration & merge decisions: credential helper list protocol (be16e27)
• docs: record original project prompt in CONTRIBUTING.md (4dba3af)
• fix: show registries from credential helpers in TUI dashboard (b5ac13c)
• chore: remove stale src/oras directory (4f494a6)
• chore: remove NuGet publishing from release pipeline (c942845)
• docs(.squad): v0.2.1 release history and decision (391a6a6)

Full Changelog: v0.2.1...v0.3.0