feat(core): add public FatAttributes constants (R/H/S/A)

[evanofficial]

Closes #1.

What

Adds a public, named FatAttributes object exposing the FAT directory-entry attribute bits (the byte at entry offset 0x0B), so callers of Fat12Volume.setAttributes and readers of Fat12Entry.attributes no longer hard-code magic numbers like 0x01 / 0x02 / 0x04 / 0x20.

Constant	Value
READ_ONLY	0x01
HIDDEN	0x02
SYSTEM	0x04
VOLUME_ID	0x08
DIRECTORY	0x10
ARCHIVE	0x20

READ_ONLY/HIDDEN/SYSTEM/ARCHIVE are the four user-settable bits setAttributes writes; VOLUME_ID/DIRECTORY are exposed read-only for callers inspecting Fat12Entry.attributes.

Changes

• New FatAttributes.kt with KDoc citing the FAT spec offset.
• setAttributes KDoc now references the named constants instead of bare hex.
• FatAttributesTest: asserts the bit values, or-combination (READ_ONLY or HIDDEN == 0x03, user mask == 0x27), and a round-trip through setAttributes -> Fat12Entry.attributes.

Notes

• Additive only — no change to any write / verify / rollback path.
• Internal DirRegion.ATTR_* constants left private as the issue requested.

Testing

./gradlew :core:test green.

Summary by CodeRabbit

• New Features

  • Added named FAT attribute constants for common directory-entry flags, making attribute handling easier and clearer for integrators.

• Documentation

  • Updated attribute-related guidance to reflect the new named constants and preserved bits.

• Tests

  • Added coverage to verify constant values, bit combinations, and attribute updates behave as expected.

[coderabbitai]

Warning

.coderabbit.yaml has a parsing error

The CodeRabbit configuration file in this repository has a parsing error and default settings were used instead. Please fix the error(s) in the configuration file. You can initialize chat with CodeRabbit to get help with the configuration file.

💥 Parsing errors (1)

Validation error: Too big: expected string to have <=250 characters at "tone_instructions"

⚙️ Configuration instructions

• Please see the configuration documentation for more information.
• You can also validate your configuration using the online YAML validator.
• If your editor has YAML language server enabled, you can add the path at the top of this file to enable auto-completion and validation: # yaml-language-server: $schema=https://coderabbit.ai/integrations/schema.v2.json

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 45c7f56c-54ad-4eeb-979c-1af8aef3e3d6

📥 Commits

Reviewing files that changed from the base of the PR and between d5f998f and 7340f07.

📒 Files selected for processing (3)

• core/src/main/kotlin/com/ams/fat12ex/core/Fat12Volume.kt
• core/src/main/kotlin/com/ams/fat12ex/core/FatAttributes.kt
• core/src/test/kotlin/com/ams/fat12ex/core/FatAttributesTest.kt

---

📝 Walkthrough

Walkthrough

A new FatAttributes Kotlin object is added exposing six public named integer constants for FAT directory-entry attribute bits (READ_ONLY, HIDDEN, SYSTEM, VOLUME_ID, DIRECTORY, ARCHIVE). The setAttributes KDoc in Fat12Volume is updated to reference these constants. A new FatAttributesTest class validates constant values, bitwise combinations, and round-trip attribute setting.

FatAttributes constants, docs, and tests

Layer / File(s)	Summary
FatAttributes object and setAttributes KDoc core/src/main/kotlin/com/ams/fat12ex/core/FatAttributes.kt, core/src/main/kotlin/com/ams/fat12ex/core/Fat12Volume.kt	New FatAttributes object defines READ_ONLY, HIDDEN, SYSTEM, VOLUME_ID, DIRECTORY, and ARCHIVE as public const val integers. The setAttributes comment is updated to reference FatAttributes-qualified names and USER_ATTR_MASK/PRESERVE_ATTR_MASK.
Constant and round-trip tests core/src/test/kotlin/com/ams/fat12ex/core/FatAttributesTest.kt	FatAttributesTest asserts each constant's exact hex value, verifies bitwise OR composites, and performs a round-trip: builds an in-memory FAT12 image, calls setAttributes, reads back Fat12Entry.attributes, and checks set/cleared bits.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~5 minutes

Poem

🐇 Six little bits in a row,
READ_ONLY, HIDDEN, all aglow,
No magic hex, just names so clear,
The FAT spec constants now appear.
Hop hop hooray, the tests are green! 🌿

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main change: adding public FAT attribute constants in core.
Linked Issues check	✅ Passed	The PR adds the requested public FatAttributes object, updates KDoc, and includes unit and round-trip tests matching the issue criteria.
Out of Scope Changes check	✅ Passed	The changes stay within the requested scope: constants, documentation, and tests, with no unrelated feature work evident.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch feat/fat-attribute-constants

---

_{Comment @coderabbitai help to get the list of available commands.}