[MakerFlyFly]

Summary

• Add the first implementation for #307: a stdlib-only, read-only magpie-discourse topic view <id|url> [--max-posts N] command for structured forum context.
• Read the requested post stream in batches of at most 20, preserve HTML bodies and reply relationships, and fail explicitly on missing posts or malformed responses.
• Include workspace, inventory and specification integration. Declare contract:mail-archive with Coverage: partial; this is not yet a complete/selectable archive backend.

Proposed delivery plan

We intend to deliver the broader issue as separate, independently useful PRs.
Each includes its implementation, tests and required documentation/integration.
The sequence and details remain open to maintainer feedback.

Step	Capability
PR1 - this PR	Read a topic and its posts
PR2	List recent topics in a category
PR3	Search forum topics
PR4	Read user profiles and recent activity
PR5	Reply after explicit user confirmation
PR6	Create a topic after explicit user confirmation
PR7	Complete the remaining mail-archive contract operations

Only PR1 is implemented here.
Skill integration, mega-topic pagination and response-byte/total-duration budgets remain follow-up design work.

Type of change

• Tool / bridge
• Python package
• Documentation

Test plan

• 213 mocked package tests; ruff check, ruff format check and mypy pass.
• Repository integration: vendor-neutrality-score 42, skill-and-tool-validator 493, dev 277, spec-validator 87 and spec-inventory 31 pass; 930 total, no skips.
• Full prek run --all-files --verbose, including offline lychee and all four workspace hooks: 40 hooks passed; 51 workspace members, 9,374 passed, 361 conditional skips, 4 deselected and 26 passing subtests.
• Magpie final-commit checklist: A-E pass, 0 blocking and 0 advisory items.
• Local zizmor 1.30.1 offline scan: no unsuppressed findings. API-dependent online audits were unavailable without a GitHub token and are not claimed as run.
• Historical anonymous CLI smoke test, 2026-10-20: topic 183261, 3 GETs, 45 unique HTML posts, boolean body markers and truncated: true. No forum writes. The bridge files are unchanged from that verified version.
• Conditional workspace skips and the absent optional Claude CLI are recorded separately; skipped checks are not counted as passes.
• Upstream PR CI has not run before this PR is opened; local results do not establish cloud-CI success.

RFC-AI-0004 compliance

• Sandbox: network reach declared; adopters allow their configured forum host.
• Vendor neutrality: vendor-specific behavior stays in the partial adapter.
• Write-access discipline: GET only, including redirects.
• Privacy LLM: no model calls; callers establish visibility and apply existing privacy approval before sending content to a model.

Linked issues

Refs #307.
This first slice does not close the broader request.

Notes for reviewers

• Every response post requires a string cooked body, including posts beyond the output cap. Explicit empty strings, whitespace and placeholders are preserved; missing/null/invalid bodies fail the whole read.
• body_hidden relays the optional boolean cooked_hidden marker, defaulting to false. It is independent of hidden; false proves neither original text nor public visibility.
• Missing requested posts fail immediately after their batch, without later requests, retries or partial success. Duplicate stream IDs are rejected. Self-consistent empty results remain valid.
• Messages follow forum stream order, which can differ from chronological archive order. truncated means only the post-count limit; it is not a byte or total-time budget. Mega topics without an ordinary ID stream are explicitly unsupported.
• Credentials stay within the configured HTTPS origin and forum path. API usernames must be ASCII; keys must encode as latin-1. Paths use one strict UTF-8 decode; encoded separators, remaining percent escapes and ambiguous paths are refused. Configured base paths must percent-encode Unicode and spaces.
• The output does not classify visibility or prove content is public. No skills, sandbox configuration, existing version numbers or CHANGELOG are changed.

AI disclosure

AI-generated PR description.
Claude Code assisted the initial prototype; Codex (GPT-6) assisted revisions, tests, validation and PR preparation.
The author has reviewed the implementation and owns this contribution.