feat: add pinned types decorator parity

[konard]

Summary

Adds universal pinned type decorator support for issue #22 and composes it into the named type decorators added on main.

Changes

• Added C# IPinnedTypes<TLinkAddress> and PinnedTypesDecorator<TLinkAddress>.
• Updated C# NamedTypesDecorator<TLinkAddress> to receive/use PinnedTypesDecorator<TLinkAddress> and implement IPinnedTypes<TLinkAddress> in addition to ILinks and INamedTypes.
• Added Rust PinnedTypesAccess and PinnedTypesDecorator parity over LinkStorage.
• Updated Rust NamedTypesDecorator to delegate link operations through PinnedTypesDecorator and expose pinned type access.
• Added C# and Rust tests covering decorator composition, pinned type enumeration/deconstruction, and invalid reserved-link validation.
• Added C# changeset and Rust changelog fragments.

Verification

• dotnet test csharp/Foundation.Data.Doublets.Cli.sln --configuration Release
• cargo fmt --all -- --check
• RUSTFLAGS=-Dwarnings cargo clippy --all-targets --all-features
• cargo test --all-features --verbose
• cargo test --doc --verbose
• node scripts/check-file-size.mjs --lang rust

Fixes #22

[konard]

Get latest changes from default branch.

Also NamedTypesDecorator should automatically include PinnedTypesDecorator (receive in constructor), so we deduplicate logic, and make each abstraction responsible for its own features.

Also we need to mirror all the same to Rust code.

We need to ensure all changes are correct, consistent, validated, tested, logged and fully meet each and all discussed requirements in widest possible sense (check issue description and all comments in issue and in pull request, make sure each and every requirement listed before actually checking if they were addressed). Ensure all CI/CD checks pass.

Please plan and execute everything in a single pull request, you have unlimited time and context, as context autocompacts and you can continue indefinetely, do as much as possible in one go, until it is each and every requirement fully addressed, and everything is totally done.

[konard]

🤖 AI Work Session Started

Starting automated work session at 2026-04-30T07:30:10.304Z

The PR has been converted to draft mode while work is in progress.

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[konard]

Solution summary

PR 46 is finalized: #46

Resolved the merge conflicts by merging latest origin/main, pushed d9d1ae2 to issue-22-889744b4, updated the PR title/body, and marked it ready for review. The PR is now MERGEABLE with merge state CLEAN.

Verification:

• Local C# tests passed: 165 tests
• Rust fmt, clippy, tests, doc tests, and file-size check passed
• Fresh GitHub CI passed for both C# and Rust pipelines on commit d9d1ae2
• Working tree is clean and synced with origin/issue-22-889744b4

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[konard]

🤖 Solution Draft Log

This log file contains the complete execution trace of the AI solution draft process.

💰 Cost estimation:

• Model: GPT-5.5
• Provider: OpenAI
• Public pricing estimate: $15.853069

📊 Context and tokens usage:

• 12.7M / 1.1M (1210%) input tokens, 33.8K / 128K (26%) output tokens

Total: (180.4K + 12.5M cached) input tokens, 33.8K output tokens, $15.853069 cost

🤖 Models used:

• Tool: OpenAI Codex
• Requested: gpt-5.5
• Model: GPT-5.5 (gpt-5.5)

📎 Log file uploaded as Repository (42514KB)

• View complete solution draft log

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Now working session is ended, feel free to review and add any feedback on the solution draft.

[konard]

✅ Ready to merge

This pull request is now ready to be merged:

• All CI checks have passed
• No merge conflicts
• No pending changes

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