Clean up CHANGELOG.md - consolidate duplicate sections and fix broken TBD links

[Copilot]

This PR addresses several organizational and structural issues in the CHANGELOG.md file that were making it difficult to read and maintain:

Issues Fixed

1. Duplicate Section Headers

The Unreleased section contained multiple instances of the same section headers scattered throughout:

• Multiple ### Changed sections
• Multiple ### Fixed sections

This made it confusing to understand what changes belonged where and violated Keep a Changelog best practices.

2. Broken TBD Placeholder Links

Many entries contained broken placeholder links like:

([#TBD](https://github.com/microsoft/wassette/pull/TBD))

These links didn't point to actual pull requests and created a poor user experience when browsing the changelog.

3. Non-Standard Section Headers

The changelog included a ### Technical Details section, which is not part of the standard Keep a Changelog format that expects only: Added, Changed, Deprecated, Removed, Fixed, and Security.

Changes Made

• Consolidated all duplicate sections: Merged all entries under single ### Added, ### Changed, and ### Fixed sections in the Unreleased section
• Removed all TBD placeholder links: Entries now either have proper PR references or none at all
• Integrated Technical Details: Moved technical implementation details into appropriate standard sections (Added and Fixed)
• Maintained chronological order: Preserved the logical flow of changes while improving organization
• Preserved existing structure: All release sections (v0.2.0, v0.1.0) and version links remain intact

The changelog now follows strict Keep a Changelog guidelines and provides a much cleaner, more professional reading experience for users wanting to understand what's new in the unreleased version.

Validation

• ✅ No duplicate section headers in Unreleased section
• ✅ No broken TBD links remaining
• ✅ All sections follow Keep a Changelog standard format
• ✅ Project builds successfully with no issues

Original prompt

Clean up the unreleased section in the CHANGELOG since they have duplicaed sections and broken links (such as TBD)

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[Mossaka]

@copilot could you please add links to every item in the CHANGELOG to refer to specific PRs that made the changes in this repo?

[Copilot]

@copilot could you please add links to every item in the CHANGELOG to refer to specific PRs that made the changes in this repo?

I understand you'd like me to add PR links to every item in the CHANGELOG. However, I'm unable to determine the correct PR numbers for entries that don't currently have them, as the repository's git history doesn't contain merge commits or other references that would help identify the specific PRs.

Many entries currently lack PR references (like the CLI UX enhancements, dependabot workflow, documentation updates, etc.), and some originally had [#TBD] placeholders that I removed during cleanup.

Could you either:

1. Provide the specific PR numbers for the missing entries, or
2. Point me to where I can find this information in the repository?

Without access to the actual GitHub PR history, I cannot accurately map changelog entries to their corresponding pull requests.