docs(rest/python): fix sample output spec URLs

[FanouZeng-TT]

Description

rest/python/client/flower_shop/sample_output/happy_path_dialog.md still
shows five discovery spec URLs using the retired nested
/specification/shopping... paths:

"spec": "https://ucp.dev/2026-01-23/specification/shopping"
"spec": "https://ucp.dev/2026-01-23/specification/shopping/checkout"
"spec": "https://ucp.dev/2026-01-23/specification/shopping/order"
"spec": "https://ucp.dev/2026-01-23/specification/shopping/discount"
"spec": "https://ucp.dev/2026-01-23/specification/shopping/fulfillment"

Each returns 404. The same-version overview, checkout, order,
discount, and fulfillment documentation paths return 200. The sample
output is copied by readers inspecting the Python client discovery response,
so these stale URLs propagate into otherwise valid example profiles.

Fix: replace only the five URLs with their reachable same-version paths.
The version, schema URLs, response structure, and capabilities without a
published replacement remain unchanged.

Category (Required)

• Core Protocol: Changes to the base communication layer, global context, or breaking refactors. (Requires Technical Council approval)
• Governance/Contributing: Updates to GOVERNANCE.md, CONTRIBUTING.md, or CODEOWNERS. (Requires Governance Council approval)
• Capability: New schemas (Discovery, Cart, etc.) or extensions. (Requires Maintainer approval)
• Documentation: Updates to README, or documentations regarding schema or capabilities. (Requires Maintainer approval)
• Infrastructure: CI/CD, Linters, or build scripts. (Requires DevOps Maintainer approval)
• Maintenance: Version bumps, lockfile updates, or minor bug fixes. (Requires DevOps Maintainer approval)
• SDK: Language-specific SDK updates and releases. (Requires DevOps Maintainer approval)
• Samples / Conformance: Maintaining samples and the conformance suite. (Requires Maintainer approval)
• UCP Schema: Changes to the ucp-schema tool (resolver, linter, validator). (Requires Maintainer approval)
• Community Health (.github): Updates to templates, workflows, or org-level configs. (Requires DevOps Maintainer approval)

Related Issues

N/A

Checklist

• I have followed the Contributing Guide (including Conventional Commits title requirements and ! for breaking changes).
• I have updated the documentation (if applicable).
• My changes pass all local linting and formatting checks.
• 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.
• (For Core/Capability) I have included/updated the relevant JSON schemas.
• I have regenerated Python Pydantic models by running generate_models.sh under python_sdk.

Screenshots / Logs (if applicable)

• parsed the sample output JSON block successfully
• verified each replaced URL returns HTTP 200 and each old URL returns HTTP 404
• uvx pre-commit run --all-files
• git diff --check