feat(dev): CodeZip dev runner and process lifecycle core

[tejaskash]

Summary

• add process lifecycle utilities for long-running local servers, including line-based logging, process-group cleanup, and SIGTERM to SIGKILL escalation
• add CodeZipDevRunner support for Python projects using uv and uvicorn --reload
• add CodeZipDevRunner support for TypeScript projects using npm and tsx watch
• pass PORT, LOCAL_DEV, and caller-provided environment variables to the agent process
• define the DevRunner interface alongside its future handler and inject process dependencies for isolated tests

Verification

• added runner coverage for missing source directories, dependency setup, command construction, and environment injection
• added process coverage for output streaming, stderr classification, shutdown, and missing executables
• bun test (565 tests)
• typecheck passes

[codecov-commenter]

Codecov Report

❌ Patch coverage is 87.00000% with 26 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (feat/project-foundation@f68b907). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
src/core/dev/run.ts	13.04%	20 Missing ⚠️
src/core/dev/process.ts	95.12%	4 Missing ⚠️
src/core/dev/port.ts	85.71%	2 Missing ⚠️

Additional details and impacted files

@@                    Coverage Diff                     @@
##             feat/project-foundation    #1883   +/-   ##
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  Coverage                           ?   96.17%           
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  Files                              ?      253           
  Lines                              ?    12455           
  Branches                           ?        0           
==========================================================
  Hits                               ?    11979           
  Misses                             ?      476           
  Partials                           ?        0           

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