Session data is keyed by absolute path, breaking context when reorganizing folders

Description

OpenCode stores per-project session data in ~/.local/share/opencode/project//storage/, where is derived from the absolute path of the working directory. Moving a project to a different folder (e.g. ~/Documents/repo → ~/Documents/new/repo) causes OpenCode to treat it as a brand-new project: the previous session history is no longer accessible from the new location, and the project appears to have lost all context.

Steps to reproduce:

Start OpenCode in ~/Documents/my-project and have a conversation.
Move the folder: mv ~/Documents/my-project ~/Documents/new/my-project.
Run opencode again from the new path.
Observe: previous sessions are not listed (opencode session list), --continue fails, and the model has no context from the prior conversation.
Expected behavior: Sessions should be tied to the project's identity, not its absolute path on disk. Reasonable identifiers:

Git remote URL (if a repo)
Repository root resolved via .git traversal
AGENTS.md / .opencode/ location
Moving or renaming the project directory should not orphan the conversation history.

Impact: Users who reorganize their folder structure (a very common operation: splitting work into subfolders, restructuring monorepos, moving projects to a new drive, syncing via symlinks, etc.) permanently lose all session context. This makes OpenCode fragile for any non-trivial workflow and forces users to either keep projects at fixed absolute paths or rely on symlinks.

Proposed solutions (any of these would help):

Key the slug by git remote URL when available, fall back to absolute path only for non-git projects.
Detect folder moves and offer to migrate/reassociate existing session data.
Add an opencode session migrate command.
Allow manual session reassociation via a config file or CLI flag.
Environment:

OS: linux/Macos
Project type: git repo

Plugins

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OpenCode version

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Steps to reproduce

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Screenshot and/or share link

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Operating System

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Terminal

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