docs: plan the product thinker's dashboard and file its follow-ups

[REPPL]

Plans the product thinker's dashboard on their interview, and files its follow-ups. Records only: no code changes.

• itd-2610032150577708 is planned (additive) with spc-2610040741034208, which has six steps. The dashboard is a private, phone-first view of the project for the product thinker, reached through their own Tailscale network. Its first version has no certificate (decision 23) and no new dependency (decision 21). The brief is at its centre: notes and "Still right" are the only writes, and everything the product thinker touches goes to the facilitator's console for review. The record covers 23 interview decisions, 8 product criteria and 7 technical checks.
• adr-2610032150581128 (proposed): abcd is reachable on a network only through the dashboard, only while someone started it, and only for people let in. It carries the security review's requirements and is accepted in step 1's change.
• Superseded: itd-139 (the static team site) and itd-2610032150580455 (Tailscale reach, folded in).
• New drafts for later:
  • itd-2610040740108331: the home network without Tailscale.
  • itd-2610040740122709: rewriting the brief and approving intents from the dashboard.
  • itd-2610040740135705: the facilitator's and the team's views.
  • itd-2610040754440360: the private dashboard for every abcd-managed project.
  • itd-2610040754453237: the public record site for every abcd-managed project.
• itd-140 records that its genericity promise is given up for now.
• Captures iss-2610032205304585 (inconsistent home folder permissions), found by the design's security review.

Refs: iss-2610032205304585

Assisted-by: Claude:claude-opus-5-5