RSPEED-2471: Use plain log handler in non-TTY environments

[major]

Description

RichHandler's columnar layout (timestamp, level, right-aligned filename) falls back to 80 columns when there's no TTY. The columns consume ~40 of those chars, leaving only ~35-40 for the actual log message. Tracebacks in containers become nearly unreadable.

Use sys.stderr.isatty() to pick the handler: RichHandler when a terminal is present (local dev), plain StreamHandler when not (containers, CI). No behavior change for local development.

Type of change

• Bug fix

Tools used to create PR

• Assisted-by: Claude

Related Tickets & Documents

• Related Issue: RSPEED-2471

Checklist before requesting a review

• I have performed a self-review of my code.
• PR has passed all pre-merge test jobs.
• If it is a core feature, I have added thorough tests.

Testing

Verified both code paths (TTY → RichHandler, no TTY → StreamHandler). All existing unit tests pass. All linters pass.

Summary by CodeRabbit

• Improvements
  • Logging output now adapts to the execution environment: interactive terminals display logs with enhanced formatting for readability, while non-interactive environments receive plain, verbose text format for better compatibility
  • Invalid log level configurations handled gracefully with fallback to defaults and warning messages instead of failures

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📥 Commits

Reviewing files that changed from the base of the PR and between 2916319 and 68fa9e6.

📒 Files selected for processing (2)

• src/lightspeed_stack.py
• src/log.py

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Walkthrough

Both files refactor logging initialization to conditionally adapt handler configuration based on TTY presence. Interactive terminals use RichHandler with simplified formatting, while non-interactive environments default to plain StreamHandler with verbose output including timestamps and line numbers.

Changes

Cohort / File(s)	Summary
Logging Configuration src/lightspeed_stack.py	Replaces unconditional logging.basicConfig with TTY-aware conditional setup. Uses RichHandler for interactive terminals with simple format; switches to verbose format with asctime, levelname, name, and lineno for non-TTY environments. Adds log level validation with fallback to default on invalid environment values.
Logger Initialization src/log.py	Refactors logger setup to check for any existing handlers before reconfiguring, not just RichHandler presence. Implements environment-aware handler selection: RichHandler for TTY, plain StreamHandler for non-TTY. Preserves propagation settings and environment variable handling for log levels.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title directly describes the main change: switching to a plain log handler in non-TTY environments, which is the core problem being solved.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

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[tisnik]

ok, interesting bug + fix. TY