auggie: enable session resume and task reporting by default

[mafredri]

Problem

Four issues:

1. Resume is off by default. The module passes --continue to auggie when continue_previous_conversation is true, but this variable defaults to false.

2. Task reporting is off by default. report_tasks defaults to false, so Auggie tasks don't benefit from activity-based TTL. This may be related to Bug: Auggie module is not reporting in task mode in latest versions #614.

3. Prompt is re-sent on resume. In build_auggie_args(), --instruction "$PROMPT" is always appended when a task prompt is set, regardless of whether --continue is also being passed. According to upstream docs, when both are passed "new instructions are appended to the resumed session" -- meaning the same task prompt gets re-sent as a new message in the resumed conversation.

4. --type is missing. The agentapi server command in start_agentapi_server() doesn't pass --type auggie.

To reproduce: set continue_previous_conversation = true, report_tasks = true, and an ai_prompt. Start the module, have a conversation, stop, restart. --instruction will be present alongside --continue, and --type will be absent from the agentapi process args.

Desired outcome

• continue_previous_conversation defaults to true.
• report_tasks defaults to true.
• The task prompt is only sent on cold start, not when resuming.
• --type auggie is passed to agentapi server.
• After feat(coder/modules/agentapi): add state persistence #736 lands: enable_state_persistence = true.

Risks

• Headless --continue is unverified. It's unknown whether auggie's --continue works correctly when wrapped by agentapi's PTY. This needs to be tested in a workspace before shipping. If it doesn't work, keep the default at false and document the limitation.
• --continue with no prior session is unverified. Unlike OpenCode (which gracefully creates a new session), auggie's behavior when --continue is passed on first run with no existing sessions is unknown. Test this.
• Backend dependency unknown. Auggie's session data may be partially stored on Augment's cloud servers. If --continue requires network connectivity, air-gapped environments can't use it.

Version bump

minor

Refs #614, #696