/draft-release: add artifact upload with pre-flight checks

Extends the draft-release command to automatically upload release
artifacts after creating the draft release. Adds sanity checks to
verify that artifacts have been downloaded and signed before proceeding.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

.claude/commands/draft-release.md

@@ -1,5 +1,5 @@
 ---
-description: Generate GitHub release notes from docs/changelog.rst and create a draft release
+description: Generate GitHub release notes from docs/changelog.rst and create a draft release with artifacts
 argument-hint: <version-tag, e.g. v0.7.0>
 model: sonnet
 allowed-tools: Read, Write
@@ -7,7 +7,7 @@ allowed-tools: Read, Write
 
 # Task
 
-Create a draft GitHub release for zrepl version $ARGUMENTS.
+Create a draft GitHub release for zrepl version $ARGUMENTS and upload release artifacts.
 
 ## Inputs
 
@@ -17,11 +17,27 @@ Here is the current changelog RST source:
 
 ## Instructions
 
-1. Extract the changelog section for version $ARGUMENTS from the RST source above.
+### Phase 1: Pre-flight Sanity Checks
-2. Extract all GitHub usernames mentioned in that changelog section (look for @username patterns or other contributor attributions).
+
-3. Write a short "Highlights" section (2-4 bullets) summarizing the most impactful user-facing changes in plain language. Do NOT include commit/issue links.
+Before creating the release, verify that the previous build steps have been completed.
-4. Write a "Contributors" thank you line for all GitHub users found in step 2. Format as: "Thanks to @user1, @user2, and @user3 for their contributions to this release!"
+Run these checks using bash commands:
-5. Write a "Breaking Changes" section. Convert RST formatting to plain Markdown text (no commit or issue links):
+
+```bash
+test -d artifacts/release && echo "✓ artifacts/release directory exists" || echo "✗ Missing artifacts/release directory - run: make download-circleci-release JOB_NUM=<num>"
+test -f artifacts/release/sha512sum.txt && echo "✓ sha512sum.txt exists" || echo "✗ Missing sha512sum.txt - run: make download-circleci-release JOB_NUM=<num>"
+test -f artifacts/release/sha512sum.txt.asc && echo "✓ sha512sum.txt.asc exists (signed)" || echo "✗ Missing signature - run: make verify-and-sign"
+ls artifacts/release/zrepl-* >/dev/null 2>&1 && echo "✓ Release artifacts present" || echo "✗ No release artifacts found"
+```
+
+If ANY check fails (shows ✗), **STOP** and print the error messages. Do not proceed with release creation.
+
+### Phase 2: Generate Release Notes
+
+2. Extract the changelog section for version $ARGUMENTS from the RST source above.
+3. Extract all GitHub usernames mentioned in that changelog section (look for @username patterns or other contributor attributions).
+4. Write a short "Highlights" section (2-4 bullets) summarizing the most impactful user-facing changes in plain language. Do NOT include commit/issue links.
+5. Write a "Contributors" thank you line for all GitHub users found in step 3. Format as: "Thanks to @user1, @user2, and @user3 for their contributions to this release!"
+6. Write a "Breaking Changes" section. Convert RST formatting to plain Markdown text (no commit or issue links):
    - `:commit:\`abc123\`` → just remove it or describe what it changed
    - `:issue:\`123\`` → just remove it or describe the issue in plain text
    - `:ref:\`display text <anchor>\`` → just use `display text` as plain text
@@ -29,15 +45,20 @@ Here is the current changelog RST source:
    - RST inline code ` ``code`` ` → markdown `` `code` ``
    - RST links `` `text <url>`_ `` → just use `text` without the link
    If there are no breaking changes, write "No breaking changes. vX.Y.Z-1 is interoperable with vX.Y.Z." (fill in actual versions).
-6. Assemble the full release notes using the template below. **IMPORTANT**: Do NOT include a detailed changelog list. Only include what is specified in the template.
+7. Assemble the full release notes using the template below. **IMPORTANT**: Do NOT include a detailed changelog list. Only include what is specified in the template.
-7. Write the result to `artifacts/release-notes.md`.
+8. Write the result to `artifacts/release-notes.md`.
-8. Validate all links in the release notes by checking HTTP status codes with curl:
+9. Validate all links in the release notes by checking HTTP status codes with curl:
    - Extract all URLs from the markdown file
    - Check each URL with `curl -sI -w "%{http_code}" -o /dev/null <url>`
    - Report any broken links (non-200 status codes)
    - If any links are broken, stop and notify the user before creating the release
-9. Run: `gh release create $ARGUMENTS --title "$ARGUMENTS" --notes-file artifacts/release-notes.md --draft`
+
-10. Print the release URL.
+### Phase 3: Create Draft Release and Upload Artifacts
+
+10. Run: `gh release create $ARGUMENTS --title "$ARGUMENTS" --notes-file artifacts/release-notes.md --draft`
+11. Upload all artifacts: `gh release upload $ARGUMENTS artifacts/release/*`
+12. Verify upload succeeded: `gh release view $ARGUMENTS --json assets --jq '.assets | length'`
+13. Print the release URL and confirm that artifacts were uploaded successfully.
 
 ## Template