feat(12-03): create whats-new.md command

- Reads installed version from VERSION file
- Fetches remote changelog from GitHub
- Displays version comparison and missed changes
- Provides update instructions when behind

.planning/ROADMAP.md

@@ -200,7 +200,7 @@ This enables execute-phase to produce more Wave 1 plans (true independence) inst
 **Plans:** 3 plans
 
 Plans:
-- [ ] 12-01: CHANGELOG.md foundation - Create changelog file, update installer to copy it
+- [x] 12-01: CHANGELOG.md foundation - Create changelog file, update installer to copy it
 - [ ] 12-02: Publish command update - Add changelog generation to gsd-publish-version.md
 - [ ] 12-03: whats-new command - Create /gsd:whats-new with remote fetch and version comparison
 

.planning/STATE.md

@@ -19,12 +19,12 @@
 
 ## Current Position
 
-Phase: 99 of 99 (Test Parallel - THROWAWAY)
-Plan: 3 of 3 in current phase
-Status: Phase complete (via parallel execution)
-Last activity: 2026-01-12 - Completed Phase 99 via /gsd:execute-phase
+Phase: 12 of 12 (Changelog & Update Awareness)
+Plan: 1 of 3 in current phase
+Status: In progress
+Last activity: 2026-01-14 - Completed 12-01-PLAN.md
 
-Progress: Test phase complete (throwaway - not counted in main milestone)
+Progress: ████████████████████░░░░ 24/27 plans (~89%)
 
 ## Performance Metrics
 
@@ -95,6 +95,7 @@ None yet.
 - Phase 9 added: Integrate verify-work (community contribution from OracleGreyBeard)
 - Phase 10 added: Parallel phase execution (rename workflow, create /gsd:execute-phase with parallelization)
 - Phase 11 added: Parallel-aware planning (update plan-phase.md to create parallelizable plans when enabled)
+- Phase 12 added: Changelog & update awareness (remote changelog fetch, /gsd:whats-new, publish workflow integration)
 
 ## Project Alignment
 
@@ -105,6 +106,6 @@ Drift notes: None
 
 ## Session Continuity
 
-Last session: 2026-01-12
-Stopped at: Completed Phase 99 via /gsd:execute-phase (parallel test)
+Last session: 2026-01-14
+Stopped at: Completed 12-01-PLAN.md
 Resume file: None

commands/gsd/whats-new.md

@@ -0,0 +1,124 @@
+---
+name: gsd:whats-new
+description: See what's new in GSD since your installed version
+---
+
+<objective>
+Display changes between installed version and latest available version.
+
+Shows version comparison, changelog entries for missed versions, and update instructions.
+</objective>
+
+<process>
+
+<step name="get_installed_version">
+Read installed version from VERSION file:
+
+```bash
+cat ~/.claude/get-shit-done/VERSION 2>/dev/null
+```
+
+**If VERSION file missing:**
+```
+## GSD What's New
+
+**Installed version:** Unknown
+
+Your installation doesn't include version tracking.
+
+**To fix:** `npx get-shit-done-cc --global`
+
+This will reinstall with version tracking enabled.
+```
+
+STOP here if no VERSION file.
+</step>
+
+<step name="fetch_remote_changelog">
+Fetch latest CHANGELOG.md from GitHub:
+
+Use WebFetch tool with:
+- URL: `https://raw.githubusercontent.com/glittercowboy/get-shit-done/main/CHANGELOG.md`
+- Prompt: "Extract all version entries with their dates and changes. Return in Keep-a-Changelog format."
+
+**If fetch fails:**
+Fall back to local changelog:
+```bash
+cat ~/.claude/get-shit-done/CHANGELOG.md 2>/dev/null
+```
+
+Note to user: "Couldn't check for updates (offline or GitHub unavailable). Showing local changelog."
+</step>
+
+<step name="parse_versions">
+From the remote (or local) changelog:
+
+1. **Extract latest version** - First `## [X.Y.Z]` line after `## [Unreleased]`
+2. **Compare with installed** - From VERSION file
+3. **Extract entries between** - All version sections from latest down to (but not including) installed
+
+**Version comparison:**
+- If installed == latest: "You're on the latest version"
+- If installed < latest: Show changes since installed version
+- If installed > latest: "You're ahead of latest release (development version?)"
+</step>
+
+<step name="display_output">
+Format output clearly:
+
+**If up to date:**
+```
+## GSD What's New
+
+**Installed:** 1.4.26
+**Latest:** 1.4.26
+
+You're on the latest version.
+
+[View full changelog](https://github.com/glittercowboy/get-shit-done/blob/main/CHANGELOG.md)
+```
+
+**If updates available:**
+```
+## GSD What's New
+
+**Installed:** 1.4.23
+**Latest:** 1.4.26
+
+---
+
+### Changes since your version:
+
+## [1.4.26] - 2026-01-20
+
+### Added
+- Feature X
+- Feature Y
+
+### Changed
+- **BREAKING:** Changed Z behavior
+
+## [1.4.25] - 2026-01-18
+
+### Fixed
+- Bug in feature A
+
+---
+
+[View full changelog](https://github.com/glittercowboy/get-shit-done/blob/main/CHANGELOG.md)
+
+**To update:** `npx get-shit-done-cc --global`
+```
+
+**Breaking changes:** Surface prominently with **BREAKING:** prefix in the output.
+</step>
+
+</process>
+
+<success_criteria>
+- [ ] Installed version read from VERSION file
+- [ ] Remote changelog fetched (or graceful fallback to local)
+- [ ] Version comparison displayed clearly
+- [ ] Changes since installed version shown (if any)
+- [ ] Update instructions provided when behind
+</success_criteria>