docs: resync with current state across all project docs

- design-guidelines: every dimension was stale — card frame 340x200
  (was 500x220), corner radius 6, title 15px at (20,30), row y0/dy,
  donut centre (250,110) r=55/30, topN=5, legend y0=55 dy=20, bar chart
  area [35,325]x[45,155], area chart [28,312]x[45,150], icon scale 0.75.
- code-standards: FetchContributionsAllTime signature now ctx-first,
  viewbox 500x220 → 340x200.
- codebase-summary: test coverage lists main_test.go +
  TestDonutSingleSlice/Empty; filename convention says plain kebab-case
  (no numeric prefix).
- project-overview-pdr: forks/private defaults now on, not off.
- project-roadmap: add Phase 7 (Marketplace polish — resize, numeric-
  prefix drop, v1 floating tag, rename-rollback). Renumber planned
  phases 8-11. Fix "hard width 500 px" limitation.
- deployment-guide: document update-major-tag job; note
  Marketplace listing name is `ghstats-cards`.

docs/project-overview-pdr.md

@@ -28,7 +28,7 @@ Distinguishing traits:
 - **Single binary**: no Node, no Ruby, no Docker needed for CLI usage.
 - **Seed-list sampling**: commit-history probes land on repos the user actually committed in (via `contributionsCollection.commitContributionsByRepository`), not top-starred or owned-only.
 - **All-time variants**: for every time-bounded card (most-commit-language, productive-time, contributions), there's a lifetime counterpart.
-- **Public-safe defaults**: forks and private repos are **off** by default; users opt in.
+- **Accurate defaults**: forks and private repos are **on** by default so cards reflect real activity; `-include-private` silently no-ops if the token lacks `repo` scope, so the default is safe for public runs too.
 
 ## Functional requirements