This commit adds three new options to 'blurb add' for automation:
- --gh_issue: Specify GitHub issue number
- --section: Specify NEWS section (must be from the sacred list)
- --rst_on_stdin: Read the news entry from stdin (no editor needed)

When using --rst_on_stdin, one must provide both --gh_issue and
--section, lest they be turned into a newt (they'll get better).

Added comprehensive test coverage including:
- Unit tests for parameter validation
- Integration tests with mock CPython repo (ruled by Brian of Nazareth)
- CLI tests that actually run the blurb command

Also fixed the command-line parser to handle non-boolean options
specifically for the add command, and improved error handling
for temporary file cleanup.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

This holy grail of refactoring reduces the code by >150 lines!
We've eliminated the bureaucracy of wrapper functions and now
apply `@app.command` decorators directly to the original functions.

Just like the Knights of Ni demanded a shrubbery, cyclopts demands
clear, typed parameters - and we have delivered! The code is now
cleaner than the Holy Grail's cup after being washed by the
French Taunter.

Key improvements:
- Moved cyclopts imports to top of file (no more silly walks)
- Applied `@app.command` directly to functions (no indirection!)
- Removed 'help' parameter from add() - cyclopts handles it
- Simplified main() from ~200 lines to ~40 lines
- Updated tests for new option naming (--gh-issue not --gh_issue)
- All 28 tests still pass - it's not dead yet!

'Tis but a scratch compared to the original implementation!

🤖 Generated with [Claude Code](https://claude.ai/code)

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

(with a few human touchups by Greg)