[BUG] kebab_filenames setting doesn't convert periods to hyphens in filenames

[divideby0]

Bug Description

When BASIC_MEMORY_KEBAB_FILENAMES=true, periods in note titles are not converted to hyphens in filenames, though permalinks work correctly.

Example

Title: "Test 3.0 Version"

Expected:

• File path: test/test-3-0-version.md ✓
• Permalink: test/test-3-0-version ✓

Actual:

• File path: test/Test 3.0 Version.md ❌
• Permalink: test/test-3-0-version ✓ (works correctly)

Root Cause

The Entity.safe_title property uses generate_permalink() which internally calls os.path.splitext(). When processing a bare title like "Test 3.0 Version":

os.path.splitext("Test 3.0 Version")
# Returns: ("Test 3", ".0 Version")

The period is treated as a file extension separator, so only "Test 3" gets kebab-cased, and ".0 Version" is appended back unchanged.

Environment

• Basic Memory version: 0.16.1 (also affects earlier versions with kebab_filenames)
• Related to PR fix: Sanitize filenames and allow optional kebab case #260 which added the kebab_filenames feature

Proposed Solution

Replace periods with hyphens before calling generate_permalink():

# In src/basic_memory/schemas/base.py
if use_kebab_case:
    fixed_title = fixed_title.replace('.', '-')  # Prevent splitext confusion
    fixed_title = generate_permalink(file_path=fixed_title, split_extension=True)

Also need to convert file_path from @property to @computed_field so it's included in Pydantic's model_dump().

Impact

Affects users with BASIC_MEMORY_KEBAB_FILENAMES=true who have version numbers or other periods in their note titles.