flagon-io/g1t

Closes #359. Follow-up to #290 (#358), which put the old workspace overview on Code's Overview: there it was closed to members without Code access and repeated what Home already shows.

Home is the one page

• Under This week, Home now shows the workspace's ground truth: what is moving and what is waiting, team by team, with the pull requests waiting on a first review, and the quiet changes (knowledge silos, new ground, spreading, new habits).
• Home reads the week's signal data once and uses it for both the week and the ground truth, so nothing is loaded twice.
• At the end of the page: Members for everyone, and Usage against the plan for owners and billing managers.
• The week's figures are not repeated: GroundTruth now takes pulse={false}.

Dollars only for billing

Owners and billing managers (managesBilling) see all the dollar figures. Everyone else does not see:

• the Spent card
• the spend-threaded-to-work section (and provider costs are not read for them)
• the Cost per agent change tile
• the "where agent spend is going" finding
• Usage

The tile row fits three tiles when the spend tile is left out.

Code's Overview is Code's again

• -/overview is back to mission control alone. The children slot on mission control is removed.
• Findings that linked to -/overview#spend or #quiet now link to -/home#….

Docs

• The Home guide gains a "The workspace" section, and notes which parts need billing.
• The workspace guide's overview section points at Home.

Checks

• Web typecheck
• Web lib tests (1204)
• prettier