factory ceo --issue <url>: target a GitHub/GitLab issue directly

[ghelleks]

Problem

Working on a specific GitHub or GitLab issue requires a multi-step workaround:

```bash
gh issue view 42 --json title,body -q '"# " + .title + "\n\n" + .body' > /tmp/issue-42.md
factory ceo /path/to/project --prompt /tmp/issue-42.md
```

There's no way to point the factory at an issue URL directly. `--focus` only accepts short strings and loses issue detail. `--issue` on `factory finalize` is metadata-only.

Proposed Solution

Add `--issue ` to `factory ceo` and `factory run`:

```bash
factory ceo /path/to/project --issue 42
factory ceo /path/to/project --issue https://github.com/owner/repo/issues/42
factory ceo /path/to/project --issue https://gitlab.com/owner/repo/-/issues/42
```

The CLI fetches the issue (via `gh issue view` or `glab issue view`), formats title + body as a spec, and passes it through the same `--prompt` pipeline — writing it to `.factory/strategy/current.md` so all agents have full context.

If `--issue` is a bare number, infer the remote from `git remote get-url origin`. If it's a full URL, detect GitHub vs. GitLab from the host.

Behavior

• Mutually exclusive with `--prompt` and `--focus` (same constraints as `--prompt`)
• Issue number is automatically recorded in `factory finalize --issue` for traceability
• `--no-github` suppresses fetching (errors out with a clear message if `--issue` is also set)

Implementation Notes

• Fetch via subprocess: `gh issue view --json title,body,labels,milestone` / `glab issue view --output json`
• Format: `# <title>\n\n` — same shape as a hand-written spec file
• Remote inference: `git -C <project_path> remote get-url origin`, then parse owner/repo from the URL

[akashgit]

Fixed in PR #213.

Instead of adding a separate --issue flag (as originally proposed), we expanded --focus to auto-detect issue references. This keeps the CLI surface minimal — --focus does the right thing based on input shape.

Usage

# By issue number (infers repo from git remote)
factory ceo /path/to/project --focus 42

# By GitHub URL
factory ceo /path/to/project --focus "https://github.com/owner/repo/issues/42"

# By shorthand
factory ceo /path/to/project --focus "owner/repo#42"

# GitLab URLs work too (including nested groups)
factory ceo /path/to/project --focus "https://gitlab.com/group/subgroup/project/-/issues/7"

# Plain backlog names still work as before
factory ceo /path/to/project --focus "dashboard UI"

What happens

1. --focus detects issue refs via pattern matching (bare numbers, URLs, owner/repo#N shorthand)
2. Fetches the issue via gh issue view (GitHub) or glab issue view (GitLab)
3. Formats title + body as a spec and writes to .factory/strategy/current.md
4. Updates the focus name to "<title> (issue #N)" for clear backlog/CEO context
5. Embeds the issue number in the CEO task so factory finalize --issue N is auto-passed
6. Runs a single-item targeted cycle (same as regular --focus)

Works with both factory ceo and factory run.