Story: Integrate support timelines and tables into every library roadmap #127

Parent Epic: #125
Depends on: #126

As a documentation reader,
I want a release timeline and a table showing support dates and PHP compatibility,
so that I can choose a branch suited to my environment and plan upgrades.

Context

Every roadmap in longitude-one/spatial-docs adopts the presentation defined by the parent Epic, including libraries without stable releases. This Story consumes the SVG generator delivered by the first Story.

Acceptance Criteria

• Every existing library roadmap displays an SVG timeline and the corresponding support table.
• The site build generates the images using the first Story's Node.js function and includes them in the built site.
• Each library's timeline and table consume the same source data; a date change appears in both on the next build.
• Each library has a JSON configuration in spatial-docs, with explicitly configured support dates and null for unannounced information.
• A global configuration defines the shared time bounds for all timelines.
• The table follows PHP.net's organization with Branch, Initial Release, Active Support Until, Security Support Until, PHP Compatibility, and Notes columns.
• Dates are absolute, with no relative durations or countdowns.
• Planned branches and their forecast dates are clearly distinguished from actual releases.
• Unannounced data is explicitly identified in the table and never produces invented values in the timeline.
• PHP compatibility is shown per branch when known and identified as unannounced otherwise.
• PHP Compatibility displays the Composer constraint configured in the branch's php field.
• The table, timeline, and legend use the site's palette and remain readable in both themes and on mobile.
• Each image has meaningful alternative text; the table has semantic headers and remains usable without the image.
• A library without a stable release displays available forecasts or an explicit state when no schedule is announced.
• The SVG and table remain available through the existing HTML and portable Markdown publication model, with working image references.

Constraints

• Depends on completion of the SVG generator Story.
• Integrate SVG images and tables into existing Markdown pages without introducing MDX components or raw HTML in source documentation.
• Generate images during the build, without client-side generation or daily refresh requirements.
• Use PHP's Supported Versions page as the presentation reference and LongitudeOne data for schedules and compatibility.
• Preserve the existing portable Markdown publication contract and explicit HTML resource paths.
• Roadmap configuration does not replace existing Packagist-based documentation version classification.

Definition of Done

The project's common Definition of Done applies.

• Inventory all roadmap pages and verify their complete migration.
• Tests verify shared table/timeline data, build-time image generation, and generated image references.
• npm test, npm run build, and applicable Markdown lint checks pass without missing assets.
• Every migrated page is visually checked in both themes; representative cases are checked on mobile.
• Document how maintainers update JSON configuration, release forecasts, support dates, PHP constraints, and global time bounds.
• Common composer test-local and composer quality checks apply only if defined in the repository; otherwise record them as not applicable to this documentation site.