fix(tui): avoid invalid dummy session id on continue

[pcgeek86]

Summary

Fixes an error where running opencode --continue fails backend schema validation:

Error: Expected a string starting with "ses", got "dummy"

Cause

When --continue was passed, RouteProvider in packages/tui/src/app.tsx initialized initialRoute with { type: "session", sessionID: "dummy" }. Mounting the session view immediately invoked sdk.client.session.get({ sessionID: "dummy" }), which failed schema validation because SessionID requires strings to start with "ses".

Solution

• Remove the hardcoded "dummy" session ID from initialRoute so that --continue waits for sync.data.session to resolve the latest valid session before navigating.
• Pass input.args.sessionID to initialRoute when --session is provided without --fork.
• Show a warning toast when --continue is used in a repository without any existing sessions.
• Update tests in packages/tui/test/app-lifecycle.test.tsx to verify no requests are made to "dummy" session IDs.

Fixes #29748

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[github-actions]

The following comment was made by an LLM, it may be inaccurate:

Potential Duplicate Found

PR #47555: fix(tui): stop fetching placeholder session id on --continue
#47555

This PR appears to be directly related to the current PR #48421. Both address issues with the --continue flag and placeholder/dummy session IDs being fetched or used incorrectly. PR #47555 specifically mentions "stop fetching placeholder session id on --continue," which seems to be addressing the same root cause of invalid dummy session IDs.

You should check if PR #47555 has already been merged or if it needs to be reconciled with the current PR #48421.

[github-actions]

This pull request has been automatically closed because it was not updated to meet our contributing guidelines within the 2-hour window.

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[pcgeek86]

This pull request has been automatically closed because it was not updated to meet our contributing guidelines within the 2-hour window.
Feel free to open a new pull request that follows our guidelines.

Ummm, ok. I literally did exactly what you asked.