feat(ui): SN74 Projects tab on /subnets/74 — registry overview and per-repo economics views with history + provenance

[JSONbored]

Problem

The data (sibling sub-issues) needs neutral, legible presentation for non-developers.

Placement

Per the epic's placement decision: a "Projects" tab on /subnets/74 (adapter-pattern sub-surface), with per-repo detail views beneath it. No standalone top-level route.

Implementation pointers (v1)

• Page: apps/ui/src/routes/-subnets-netuid-page.tsx — use the existing ProfileTabs / useActiveTab machinery
• The tab is conditional: rendered only when the subnet has registry sub-entity data (v1: netuid 74 via the sn74-registry adapter artifact). Respects the feat(ui): subnet detail rebuild — identity header, 6-KPI band, 7 lazy tabs, zero duplicate facts #8247 tab consolidation — no page changes for any other subnet
• Data source v1: the adapter artifact (no new endpoints); per-repo expand renders the param timeline with commit-linked values
• Visual-change PR conventions apply (screenshot table)

Scope

• Projects tab on /subnets/74: all registered repos with current emission share, maintainer cut, and scoring-window summary; sortable; uniform presentation for every repo
• Per-repo page: current full configuration, a parameter-history timeline (what changed, when, linked to the source commit), and plain-language field explanations sourced from upstream docs
• Every displayed value links to its provenance (upstream commit)
• Standard UI conventions apply (screenshot table on the PR; held for manual review per visual-change policy)

Acceptance

A non-developer can answer "what are this repo's parameters and how have they changed?" in two clicks, and verify any value via its commit link.

[linear-code]

JSO-6813