chore: standardize module examples to use coder_agent.main

[blinkagent]

Summary

This PR standardizes all module documentation examples to use coder_agent.main instead of coder_agent.example, aligning with the most common template convention.

Problem

Currently, there's an inconsistency between template definitions and module documentation:

• Templates: 78% (21 of 27) use "main" as the agent name
• Module documentation: Most of examples use "example" as a placeholder, which doesn't exist in any templates, except some modules who already use "main"

This creates friction when users copy examples from module docs into their templates that use main as the agent name.

Solution

Update all module documentation to use coder_agent.main since:

1. It matches the most common convention (21 of 27 existing templates)
2. Creates consistency between docs and real-world usage
3. Reduces the need for users to edit copy-pasted examples

Changes

Module Documentation (52 files)

• ✅ Updated 50+ module README.md files from coder_agent.example → coder_agent.main
• ✅ Updated root README.md
• ✅ Updated CONTRIBUTING.md
• ✅ Updated examples/templates/main.tf

What's NOT in this PR

❌ Template changes - Templates are left as-is to avoid breaking existing workspaces
❌ Linting rules - Will be addressed separately if desired

Impact

✅ Zero breaking changes: Only documentation is updated
✅ Better DX: Copy-paste examples work with 78% of existing templates
✅ Consistency: Documentation now matches the de facto standard

Testing

• ✅ All changes verified with git diff
• ✅ Only modified documentation files (52 files changed)
• ✅ 200 insertions, 200 deletions (pure substitution)

Related

This addresses the documentation inconsistency identified in the registry audit. Template standardization can be addressed in a future PR if desired.

PR by @phorcys420

[phorcys420]

also, do we want linting rules for this as well?

[DevelopmentCats]

also, do we want linting rules for this as well?

If its not a huge task to add it wouldn't be a bad idea.

[DevelopmentCats]

@phorcys420 one thing we need to consider here is that none of these changes will reflect on the registry unless we are actually bumping the version of every single module we updated.

[DevelopmentCats]

I should add that if you wanted to just do a patch version bump we could just run the version bump script with the patch flag and it should automatically update all the versions so we can do releases for this easily

[phorcys420]

@DevelopmentCats yeah, i can bump, i'll do another PR myself instead cause blink is going crazy rn, sorry for the noise haha