fix(compile): resolve pickle error and merge skill_name changes

[fujiajie666]

Description

Fixes the OpenViking ov compile failure [INTERNAL] cannot pickle '_thread.lock' object,
and merges the upstream skill_name prompt changes from commit 6aab476. Also relaxes the
compile renderer's reserved-filename set so Skill-defined outputs like index.md are no
longer rejected.

Human Involvement

• A human participated in the implementation or review loop
• This PR was generated entirely by AI agents without human participation in the loop

Related Issue

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Refactoring (no functional changes)
• Performance improvement
• Test update

Changes Made

• Fix cannot pickle '_thread.lock' object in BotCompileService: replace the full
  model_copy(deep=True) (which deep-copied a VLMConfig holding an unpicklable
  threading.Lock) with a shallow copy that only resets skills and deep-copies the
  sandbox subtree.
• Thread a skill_name parameter through _build_prompts and add a skill_read_rule
  instructing the agent to read Skill package files via read_file under
  skills/<skill-name>/ instead of openviking_* tools (merged from upstream 6aab476).
• Add the corresponding Skill-workspace read redirect hint/error in
  agent/tools/compile.py and a design-doc note in docs/design/ov-compile-design.md.
• Shrink _RESERVED_FILENAMES in compile/renderer.py to only .abstract.md /
  .overview.md, so Skill-produced files such as index.md are allowed.

Testing

• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have tested this on the following platforms:
  • Linux
  • macOS
  • Windows

bot/tests/test_compile.py — 83 passed locally (pytest bot/tests/test_compile.py),
including new tests for skill-workspace read redirection and the skill_name prompt wiring.

Checklist

• My code follows the project's coding style
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• Any dependent changes have been merged and published

Additional Notes

Root cause of the pickle error: a threading.Lock private attribute was added to
VLMConfig (_media_semaphore_lock) on 8-3, which made any model_copy(deep=True) of the
compile task config fail. The chat path is unaffected because it never deep-copies the
config; this change is compile-only.