fix: consolidate unresolved review feedback from PRs #4, #6, #26

[Copilot]

Addresses all actionable, unresolved review comments across the three substantive open PRs to unblock merging.

xapi.ts — type safety & robustness (PR #26)

• Replace string-concatenated mentions URL with URLSearchParams; add since_id pagination tracking
• Add Array.isArray() guard in fetchThread() before parseThread() to handle non-array API responses
• Type parseThread param as { created_at: string; [key: string]: unknown }[] instead of any[]
• Use [...tweets].sort() to avoid mutating the input array

agent.ts — memory bounds & correctness (PRs #26, #6)

• Add MAX_PROCESSED_MENTIONS cap with safe iterator pruning using { value, done } destructuring (no type assertions)
• Process mentions oldest-first ([...newMentions].reverse()) so Set insertion order matches chronological order
• Pass mention.post.id as mentionPostId to analyzeAndDecide

grok.ts — reply targeting & type safety (PR #6)

• Add mentionPostId parameter to analyzeAndDecide so replies target the mention post, not the thread root
• Replace const data: any with a typed assertion for the Grok API response

index.ts — stdout/stderr separation (PR #26)

• Redirect console.log to stderr (unknown[], no unused origLog binding) to avoid corrupting MCP stdio transport

README.md (PR #4)

• Fix broken list numbering in xAI/Grok API key section

// Safe iterator pruning pattern (agent.ts)
const { value, done } = iter.next();
if (done) break;
this.processedMentions.delete(value);

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[groupthinking]

Closing stale draft — superseded by cleanup/ready-to-use merge to main