fix(kimaki): point opencode.json plugin paths at persistent kimaki-config dir on local

[chubes4]

Summary

• Point local OpenCode plugin entries at $KIMAKI_DATA_DIR/kimaki-config/plugins instead of npm package-local kimaki/plugins paths.
• Stop local Kimaki sync/post-upgrade from relying on npm-dir plugin restoration; post-upgrade now validates the persistent plugin target while retaining skill restoration.
• Rewrite stale managed plugin entries during opencode.json repair so existing installs migrate on the next upgrade run.

Problem

npm update -g kimaki wipes $(npm root -g)/kimaki/plugins/, and macOS local installs have no launchd ExecStartPre hook to restore it. When dm-context-filter.ts disappears, Kimaki bridge content such as --worktree, --cwd, scheduled sends, and worktree creation instructions leaks into agent system prompts unfiltered.

Reproducer

Observed ENOENT failures in kimaki.error.log on May 2 and May 5 while OpenCode tried to load npm-dir plugin paths:

path=file:///Users/chubes/.nvm/versions/node/v24.13.1/lib/node_modules/kimaki/plugins/dm-context-filter.ts ... ENOENT

Root cause

Local installs had a plugin path mismatch:

• Persistent source: $KIMAKI_DATA_DIR/kimaki-config/plugins/, which survives npm update -g kimaki.
• OpenCode-loaded path: $(npm root -g)/kimaki/plugins/, which is package-local and gets wiped by npm updates.

Fix

• Generate local opencode.json entries directly against $KIMAKI_DATA_DIR/kimaki-config/plugins/<plugin>.ts.
• Remove the local npm-dir plugin mirror from bridge_sync_config.
• Make post-upgrade.sh validate persistent plugin files by default instead of restoring them into npm package-local paths.
• Teach additive/full opencode.json repair to rewrite managed plugin entries whose basename is dm-context-filter.ts or dm-agent-sync.ts when they point outside the persistent plugin directory.
• Run opencode.json drift/repair during --kimaki-only upgrades so the documented repair command actually exercises the migration.

VPS impact

None expected. VPS installs already use /opt/kimaki-config/plugins as the durable OpenCode plugin target, so the persistent source and loaded plugin path remain the same.

Tests added

• Added tests/opencode-local-plugin-path.sh for local-mode opencode.json plugin generation.
• Extended tests/repair-opencode-json.sh to verify additive repair rewrites stale npm-dir managed plugin paths.
• Updated tests/post-upgrade-restore.sh for the new persistent-plugin validation behavior.
• Refreshed effective-prompt snapshots for the current Kimaki prompt text; filtered leak count remains zero.

Test status

• bash upgrade.sh --kimaki-only --dry-run --wp-path /Users/chubes/Studio/intelligence-chubes4
• bash upgrade.sh --kimaki-only --repair-opencode-json --dry-run --wp-path /Users/chubes/Studio/intelligence-chubes4
• for test_script in tests/*.sh; do bash "$test_script"; done
• node tests/effective-prompt/run.mjs
• homeboy test

AI assistance

• AI assistance: Yes
• Tool(s): OpenCode (GPT-5.5)
• Used for: Implementing the patch, writing focused regression tests, running dry-run/test validation, and drafting this PR summary. Chris remains responsible for review and merge.