feat: add access logging to secret fetches

[narenaryan]

Description

This PR adds logging to Whispr package while fetching secrets. Log format will be like this:

2025-12-30T23:49:52.158353Z [info ] Secret fetched fetched_at=2025-12-30T23:49:52.158275+00:00 secret_name=my-secretvault_type=aws-ssm

Default logging paths:

1. Mac OSX: ~/Library/Logs/whispr/access.log
   2.Windows: C:\ProgramData\whispr\access.log
2. Linux: /var/log/whispr/access.log

[coveralls]

Pull Request Test Coverage Report for Build 20608625246

Details

• 46 of 53 (86.79%) changed or added relevant lines in 5 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+1.6%) to 76.168%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/whispr/about.py	0	1	0.0%
src/whispr/aws.py	9	10	90.0%
src/whispr/logging.py	31	36	86.11%

Totals
Change from base Build 16819321292:	1.6%
Covered Lines:	326
Relevant Lines:	428

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💛 - Coveralls