fix: support short-format URI paths in VikingURI and VikingFS

[fengjunhui]

Summary

Fixes #259

• Auto-normalize short-format URIs (e.g., /resources, user/memories) to full viking:// format in VikingURI.__init__, leveraging the existing VikingURI.normalize() method
• Add URI normalization in VikingFS._is_accessible() so access checks no longer reject valid short-format paths
• Add 11 unit tests covering short-format URI parsing and normalization

Changes

File	Change
openviking_cli/utils/uri.py	Call normalize() in __init__ before parsing
openviking/storage/viking_fs.py	Call VikingURI.normalize() in _is_accessible()
tests/test_uri_short_format.py	New: 11 tests for short-format URI support

Test plan

• VikingURI("/resources") → viking://resources (was ValueError)
• VikingURI("user/memories") → viking://user/memories (was ValueError)
• VikingURI("viking://resources") unchanged (no regression)
• Invalid scope still raises ValueError
• client.ls("/resources") works end-to-end (was PermissionError)
• All 11 new unit tests pass

🤖 Generated with Claude Code

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[fengjunhui]

Closing in favor of #281 which already addresses this issue with a more comprehensive fix. Thanks!