fix(scripts): create agent slots from origin/main, not the removed dev branch

[Leo310]

What

bun run setup-slots failed with fatal: invalid reference: dev whenever it had to (re)create a slot worktree. The repo is main-only now. The script now runs git fetch origin main once and creates missing slots from origin/main. It also runs git worktree prune before worktree add, so a slot directory deleted by hand (which leaves a stale registration behind) can be recreated. The dispatch skill's post-merge git pull --ff-only origin dev now pulls main too. claim-slot.sh, release-slot.sh and AGENTS.md "Parallel agent slots" had no stale dev references (AGENTS.md already says origin/main).

How I tested it

Scripts only, no plugin code. bash -n on the script. Replayed the worktree step against a scratch path: created a worktree from origin/main, deleted its directory, and confirmed worktree add fails without the prune and succeeds with it. Existing slots are untouched: the -d "$worktree" guard is unchanged, so the script stays idempotent. I did not re-run the full script because all three slots are currently claimed and it would rebuild them.

AI assistance: Claude Code wrote the change from Leo's brief to fix the stale dev reference in setup-slots; Leo reviews it.

Checklist

• bun run check, bun run format, bun run lint, and bun run test pass locally (n/a: no TS/Svelte touched)
• I tried the change in a real Obsidian vault (or explained above why that isn't applicable)
• I read CONTRIBUTING.md, including the section on AI assistance
• If this adds a provider, a bundled skill, a built-in tool, or changes manifest.json: I noted that the docs site needs updating (see "Documentation" in CONTRIBUTING.md)

[greptile-apps]

Confidence Score: 5/5

[Medium risk] Updates agent slot setup to use main branch instead of dev.

The PR appears safe to merge; the previously reported fetch failure for existing-slot maintenance is fixed.

Summary

The PR creates missing agent slots from origin/main, prunes stale worktree registrations before recreation, and updates the dispatch skill’s post-merge pull to use main. The follow-up change fetches only when a slot needs creating, preserving offline maintenance of existing slots.

_{Reviews (2) · Last reviewed commit: "fix(scripts): only fetch origin/main whe..."}