feat: scaffold standalone Maddox Think application

[brandonbryant12]

What

Adds a self-contained scaffold under scaffolds/maddox-think/ for a brand-new company-agent application built on Cloudflare Think, idiomatic Effect TypeScript, and Alchemy Infrastructure-as-Effects.

This is intentionally staged in the Effect template because the connected GitHub installation does not expose repository creation. The intended destination is a new private repository such as card-madness/maddox-think; this PR should not be merged into Card Madness or the current Maddox/Hermes deployment.

Architecture

• one MaddoxConversationAgent Think Durable Object per verified Slack thread;
• Think owns conversation/session durability, model turns, tools, actions, and scheduling;
• Effect owns contracts, tagged failures, services, adapters, policy, authorization, memory, retries, and delivery;
• Alchemy is the only infrastructure authority—no Wrangler configuration;
• D1 stores principals, role grants, channel policy, and the conversation directory;
• Think SQLite remains thread-local runtime state;
• GBrain/Neon remains the shared company-memory authority;
• reads become tools and external writes become Think Actions;
• Workflows and on-demand Sandbox are later slices, not launch dependencies.

Included

• Alchemy stack for Worker, Think DO binding/migration, Workers AI, D1, R2, secrets, and observability;
• signed Slack Events API ingress and stable thread identity;
• thin Think agent class and Think-to-Effect managed runtime seam;
• Effect Schema contracts, tagged errors, service ports, and deterministic placeholders;
• first D1 registry migration;
• architecture guard script;
• baseline Card Madness company-operating-system skill;
• ADRs for the Think/Effect boundary and thread-per-agent identity;
• detailed component plan from the first conversational canary through Actions, memory, skills, Workflows, and Sandbox;
• explicit, reviewable import design for selected state from local Hermes only.

Hermes posture

No dependency on or migration from the existing cloud-hosted Hermes deployment. A future administrative importer may take only selected SOUL/profile text, reviewed skills/resources, curated memory candidates, and optional summaries from the local Hermes instance. OAuth state, API keys, cookies, SQLite databases, caches, binaries, and old cloud recovery state are explicitly excluded.

Validation performed

• branch contains one commit, 26 added files, and no changes outside scaffolds/maddox-think/;
• all JSON files were parsed successfully;
• all TypeScript files passed a TypeScript syntax-only transpile parse;
• current Alchemy async Worker, Workers AI binding, Durable Object, Think submission, scheduled-task, and Think Actions examples were reviewed while shaping the scaffold.

A dependency install, full typecheck, Workerd test, Alchemy plan, and deployment were not run in this connector-only staging environment. Those are the first acceptance gates after extracting the scaffold into the new repository and generating its lockfile.

Extraction

Copy the contents of scaffolds/maddox-think/ to the root of the new private repository, then implement Milestone A from docs/implementation-plan.md before enabling any external write action.