fix(reports): header 「生成报告」 joins the report disabled-button rule (BUG-1078)

The generate button renders in SecondaryPageShell's actions slot, outside the
report roots, so while submitting it still got the global 45% fade. A
report-owned `report-center-generate` class brings it into the disabled rule;
SecondaryPageShell and button.tsx unchanged.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017eEAG8HD3mm8gsKXgk8uU8

frontend/DESIGN.md

@@ -543,7 +543,7 @@ one skeleton, none of them carrying the sidebar.
 
 ### Personal report reader
 
-- **Buttons on the report surfaces (2026-09-28, BUG-1078):** the list, the reader with its export dialog, and the loading / state / error / not-found screens restyle the shared `Button` locally; `components/ui/button.tsx` and the theme tokens are untouched, so other pages keep the shared primary. Cause: the unlayered `button { color: inherit; }` beats Tailwind's layered `text-primary-foreground`, so a solid `<button>` shows the page ink — #1d1d1f on #a9583e in light (3.33:1, the reported black-on-dark-red) and #f2f0ea on #d78064 in dark (2.57:1); `<Button render={<Link/>}>` renders an `<a>` and was never affected. Solid (`variant="default"`) now sets its own label colour: light #fbfaf7 on `--color-action` #a9583e (4.85:1); dark `--color-ink` #f2f0ea on `--color-action-on-dark` #8f4a33 (5.77:1), hover mixes 6% ink in (5.1:1). Disabled, any variant: `--color-canvas-strong` fill + `--color-ink-tertiary`, opacity 1 instead of the global 45% fade. The selected export preset is `--color-canvas-muted` + `--color-ink` + a `--color-ink-secondary` edge, not the `--color-action-soft` fill (a red-brown block in dark mode).
+- **Buttons on the report surfaces (2026-09-28, BUG-1078):** the list, the reader with its export dialog, and the loading / state / error / not-found screens restyle the shared `Button` locally; `components/ui/button.tsx` and the theme tokens are untouched, so other pages keep the shared primary. Cause: the unlayered `button { color: inherit; }` beats Tailwind's layered `text-primary-foreground`, so a solid `<button>` shows the page ink — #1d1d1f on #a9583e in light (3.33:1, the reported black-on-dark-red) and #f2f0ea on #d78064 in dark (2.57:1); `<Button render={<Link/>}>` renders an `<a>` and was never affected. Solid (`variant="default"`) now sets its own label colour: light #fbfaf7 on `--color-action` #a9583e (4.85:1); dark `--color-ink` #f2f0ea on `--color-action-on-dark` #8f4a33 (5.77:1), hover mixes 6% ink in (5.1:1). Disabled, any variant: `--color-canvas-strong` fill + `--color-ink-tertiary`, opacity 1 instead of the global 45% fade. The header 「生成报告」 sits in the `SecondaryPageShell` actions slot, outside those roots, and joins the disabled rule through its own `report-center-generate` class. The selected export preset is `--color-canvas-muted` + `--color-ink` + a `--color-ink-secondary` edge, not the `--color-action-soft` fill (a red-brown block in dark mode).
 - **分块导出对话框 (2026-09-24):** native modal `<dialog>`, bottom-aligned below 860px and centered at ≥860px, app colours only. Desktop is viewport-centered (`inset: 0; margin: auto`) regardless of sidebar state, width `min(720px, 92vw)`, max-height 80vh, with full `--radius-lg` corners. Its flex panel is capped at `calc(80vh - 2px)` to reserve the dialog border; desktop rules follow the narrow-screen dvh upgrade so 70dvh cannot override them. Below 860px the content-column offset, bottom alignment and at most 70vh/70dvh remain unchanged. Header and single export footer stay visible; the block list scrolls, two columns at the existing 860px breakpoint. Escape, backdrop or 关闭 dismisses; focus returns without scrolling. All controls have 44px targets. No spinner, clipboard or extra fetch.
 - **Export selection:** default 常用 selects every body block from the single outline's lossless source slices (lead = 摘要); 全部分盘 and 仅核对表 replace the selection. Manual toggles clear preset highlighting. 全选 / 取消全选 works across all groups; zero selected disables export. Counts are actual Unicode code points in serialized block text, including SVG markup, not approximate prose counts.
 - **Export content:** full body alone remains byte-identical to the retired ordinary Markdown export. Selected chart/table blocks append new content; selecting all groups is not byte-identical to body-only. D13 requires safe SVG in each chart, reusing the projected engine SVG or the existing hook-free Vedic drawing; offline fallback uses readable monochrome glyphs/legend and presentation attributes. No chart JSON fences or internal audit fields. Fact-table labels/precision/subtables match the reader. Full body uses the historical filename; excerpt adds `-节选`. The existing downloader appends `.md`.