fix(sync): suppress OpenCode SHM-only daemon watch pushes

[rodboev]

Daemon-delegated watch pushes currently treat every filesystem batch as dirty, so OpenCode's WAL shared-memory index can retrigger a zero-session push after the daemon reads a quiet database. The repeated opencode.db-shm sequence came from @ngocphamm's report.

This adds a provider-owned changed-path relevance check at the push trigger boundary. OpenCode-family SHM-only events become no-ops while checkpointed database writes and WALs containing frames continue to trigger synchronization. The existing provider classification from #956 remains the source of the SHM and WAL rules, and authoritative recovery batches continue to push.

All four watch notification owners route through the same gate: daemon PostgreSQL, daemon DuckDB, local PostgreSQL, and local DuckDB. Filesystem event delivery, local archive synchronization, coverage-degradation notification, startup and interval pushes, storage, and mirror schemas remain unchanged.

Closes #1317

[roborev-ci]

roborev: Combined Review (f7f421b)

The change is incomplete: daemon DuckDB watches still trigger pushes for irrelevant OpenCode-family sidecar events.

Medium

• cmd/agentsview/archive_write_backend.go:567 — The daemon DuckDB watch path calls the unfiltered notifier, so OpenCode-family SHM-only batches continue scheduling repeated DuckDB pushes. Use notifyPushForWatchBatchWithConfig(callbackCtx, loop, b.appCfg, batch) here as in the PostgreSQL path, and add daemon DuckDB coverage.

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Reviewers: 2 done | Synthesis: codex, 9s | Total: 3m34s

[roborev-ci]

roborev: Combined Review (1d15d5a)

No issues found.

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Reviewers: 2 done | Synthesis: codex | Total: 4m45s

[roborev-ci]

roborev: Combined Review (695ecd0)

Medium-severity issue found in OpenCode watch-path relevance handling.

Medium

• cmd/agentsview/archive_write_backend.go:323 — filepath.Clean converts both an empty root and an explicitly configured current-directory root (".") to ".", causing opencode_dirs = ["."] to be excluded from relevance checks. The watcher may still monitor this root through its fallback path, leaving SHM-only events unsuppressed and allowing the push feedback loop to continue. Reject empty roots before cleaning, preserve explicit "." roots, and add coverage for current-directory configuration.

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Reviewers: 2 done | Synthesis: codex, 7s | Total: 6m25s