fix: resolve mapped jsr with path correctly

[hasundue]

• chore(cli): add --debug option
• chore: better error message for unresolved import
• test: add a failing case (mapped jsr with path)

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 68.42105% with 6 lines in your changes are missing coverage. Please review.

Project coverage is 84.79%. Comparing base (d254e48) to head (f8c300c).

Files	Patch %	Lines
core/update.ts	0.00%	5 Missing :warning:
core/dependency.ts	85.71%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #145 +/- ## ========================================== - Coverage 85.30% 84.79% -0.51% ========================================== Files 10 10 Lines 1184 1197 +13 Branches 209 212 +3 ========================================== + Hits 1010 1015 +5 - Misses 172 180 +8 Partials 2 2 ```

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