fix: emit per-model log lines for dbt clone

[claygeo]

Summary

Fixes dbt-labs#9501

dbt clone ran completely silent — no per-model output, no way to tell which models were being cloned vs skipped as no-ops, and no visibility into errors until the end-of-run summary.

This adds before_execute / after_execute implementations to CloneRunner following the same pattern as ModelRunner:

• START line when each model begins cloning
• Result line when it finishes, showing:
  • The adapter response (e.g. CREATE TABLE) when a clone was created
  • No-op when the relation already matched the source
  • Error details at ERROR level when cloning failed

Before:

Running with dbt=1.9.0
...
Done. PASS=42 WARN=0 ERROR=0 SKIP=0 TOTAL=42

After:

Running with dbt=1.9.0
Concurrency: 4 threads (target='dev')

1 of 42 START clone model.my_pkg.model_a ................ [RUN]
1 of 42 OK clone model.my_pkg.model_a ................... [No-op in 0.23s]
2 of 42 START clone model.my_pkg.model_b ................ [RUN]
2 of 42 OK clone model.my_pkg.model_b ................... [CREATE TABLE in 0.41s]
...
Done. PASS=42 WARN=0 ERROR=0 SKIP=0 TOTAL=42

Test plan

• python -m pytest tests/unit/task/test_clone.py -v — 5 tests pass
• Manual: run dbt clone --state ./prod-artifacts and verify per-model output appears