fix: use 365-day annualisation for Sharpe ratio

Energy markets operate every day of the year, unlike equities where
252 trading days is the convention. Updated the annualisation factor
in compute_sharpe() and the corresponding notebook walkthrough.

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

Author: tommed

.claude/commands/release.md

@@ -3,6 +3,6 @@ Create release: $ARGUMENTS
 1. Read @README.md and @CONTRIBUTING.md file to understand how to publish this release.
 2. Bump version in pyproject.toml
 3. Perform the git cli commands
-4. Use gh to create the release and publish
+4. Use gh to create the release and publish (allow gh to generate notes)
 
 NOTE: The PR will run a few guardrail checks, so you'll need to wait for these to complete before merging.