- Correct `begin` mapping in the `hbmon_log_last` upsert query.
- Adjust error message in `job_feed_daemon_status.go` for `heartbeatToDB` to improve clarity.

…atus`

- Add checks for unregistered nodes and peer-nodes with detailed debug logging.

Refactor row count handling by introducing `ExecContextAndCountRowsAffected` on cdb.DB
- Simplify row count handling in `job_feed_system.go` and `job_feed_node_disk.go` by replacing redundant code with `ExecContextAndCountRowsAffected`.
- Add `ExecContextAndCountRowsAffected` utility function to `cdb/db.go` for consistent query execution and row count retrieval.
- Fix nil pointer
    panic: runtime error: invalid memory address or nil pointer dereference
    [signal SIGSEGV: segmentation violation code=0x1 addr=0x20 pc=0xceda8e]

    goroutine 2289 [running]:
    github.com/opensvc/oc3/worker.(*jobFeedSystem).targets(0xc0003ec000, {0x2303e98, 0x29b12c0})
        .../worker/job_feed_system.go:157 +0x4ce
    github.com/opensvc/oc3/worker.runOps({0x2303e98, 0x29b12c0}, {0xc0000945a0?, 0x0?, 0xc0000360f0?})
        .../worker/base_job.go:89 +0xf7
    github.com/opensvc/oc3/worker.RunJob({0x2303e98, 0x29b12c0}, {0x2302858, 0xc0003ec000})
        .../worker/base_job.go:52 +0x285
    github.com/opensvc/oc3/worker.(*Worker).runJob(0xc0003b6e10, {0xc0003e2260, 0x2, 0x0?})
        .../worker/worker.go:202 +0x1306
    github.com/opensvc/oc3/worker.(*Worker).Run.func1.1({0xc0003e2260?, 0x0?, 0x0?})
        .../worker/worker.go:96 +0x5c
    created by github.com/opensvc/oc3/worker.(*Worker).Run.func1 in goroutine 32
        .../worker/worker.go:94 +0x67

…t` utility in `cdb`.

- Replaced verbose `ExecContext` and `RowsAffected` logic with `execCountContext` for consistent row count retrieval across database operations.
- Improved code clarity and reduced redundancy across several modules in `cdb`.
- Fix potential nil pointer dereference in the result returned by execContext