#3423 Docs: document swamp start onboarding and the local dashboard

Problem

swamp start (swamp-club#3261, #3366) and the local dashboard (swamp-club#3379) have shipped, but the public manual has no entry for either CLI surface.

This leaves the recommended first-run path inconsistent:

• how-to/install-swamp.md still sends users to swamp auth login and swamp repo init; a first interactive install now starts swamp start, which handles sign-in itself, creates or imports a workspace, captures a task, and launches a selected local agent.
• reference/swamp-account-requirement.md says every command other than the listed exemptions requires a credential. swamp start is intentionally exempt so its page can sign the user in.
• reference/swamp-serve/dashboard.md describes the dashboard as available only through swamp serve --dashboard; it has no local-CLI mode, behavior URLs, or explanation of the views that are unavailable locally.

The README has a short swamp start introduction, but it cannot replace discoverable manual reference and task guidance.

Documentation to add or update

Start and workspace onboarding

Add a discoverable manual guide for swamp start and link it from Install Swamp and the AI Agents landing page. It should cover:

• swamp start as the recommended interactive desktop first-run path; it opens a loopback browser page and signs in within that flow.
• Creating a named workspace under ~/.swamp/workspaces/ (or $SWAMP_HOME/workspaces/) versus importing an existing Swamp repository without moving it.
• The task flow: create/select a workspace, describe a task, choose an installed supported agent, and the task brief kept at tasks/<date>-<slug>.md.
• Returning to tasks and launching/resuming an agent; swamp start status and --workspace <name> as the non-destructive inspection/direct-open commands.
• Ctrl-C and --no-browser behavior, plus the fact that a task can be opened by more than one swamp start process.
• The distinction from swamp repo init: start is the guided onboarding path; repo init remains the direct, existing-project/per-agent setup path.

Update reference/swamp-account-requirement.md to list swamp start as exempt and explain that its browser flow requires sign-in before it creates/imports a workspace, enrolls agents, or launches one.

Local dashboard

Extend reference/swamp-serve/dashboard.md (or split out a linked local-dashboard reference) to distinguish:

swamp dashboard
swamp dashboard --repo-dir <dir>
swamp dashboard --no-browser

from swamp serve --dashboard:

• Local dashboard needs no running swamp serve and no dashboard login; it opens one initialized local repo and does not register it as a swamp start workspace.
• From swamp start, Open dashboard serves registered workspaces with a workspace picker and a link back to workspaces/tasks.
• Local mode is read-only for normal dashboard data; the supported workflow actions are approve, reject, resume, and cancel, executed through the CLI so normal repository locking and sync semantics apply. A resumed workflow continues after the dashboard closes.
• Schedules and Webhooks are deliberately unavailable locally; Logout and Serve Configuration are absent. Direct swamp serve --dashboard remains the route for serve-only features.
• --json is refused because swamp dashboard produces a browser page, not structured output.
• The canonical behavior routes are /dashboard/behaviors/...; legacy /dashboard/models/... routes continue to resolve.

Keep the existing swamp serve --dashboard configuration, authentication, and remote-dashboard URL material intact; the new material must make the two modes easy to choose between.

Sources

• swamp-club#3261 — swamp start onboarding
• swamp-club#3366 — task/workspace navigation and agent selection refinements
• swamp-club#3379 — local dashboard via swamp start and swamp dashboard
• design/surfaces/start.md
• design/surfaces/local-dashboard.md