Add Orchestration Docs - #26

Rewrite Getting Started to match the actual UI: top-level
Orchestration sidebar item with five tabs (Jobs, Pipelines, Run
History, DAG, Overview). Replace stray "Administration > Pipelines",
"pipeline list", and "Run-Now" references with the real tab names.
Consolidate the redundant "Run-Now and Manual Triggers" heading
into "Manual Triggers". History section now points readers at the
Run History tab and notes it spans both jobs and pipelines.

Adds eight images to static/img/orchestration/ and inline references
in orchestration.md at the spots previously marked with SCREENSHOT
comments — Jobs tab list, Pipelines design view with step properties,
parameter declaration + filled values, SQL editor with placeholders
and the param prompt modal, Run History list + run results, and the
Schedule modal with overlap policies. Also fixes a markdown table cell
where the pipe in the {{ region_code | lower }} example broke the row;
now uses HTML entities so the literal pipe renders inside the inline
code without escaping artifacts.

Adds a Views section just before Permissions, with subsections covering
the two tabs that were previously only mentioned in the Getting Started
bullet list. Each subsection explains the tab's purpose and includes
"use this when" bullets so readers can tell at a glance whether they
should be on that tab. Two screenshots — orchestration_dag.png and
orchestration_overview.png — anchor the prose.

Adds a blockquote at the top flagging that orchestration features
(pipelines, the Orchestration sidebar entry, Run History / DAG /
Overview tabs, and pipeline-aware parameter propagation) require
2026.06.001 or later. Links to new.md so readers on older installs
know where to find the upgrade context. Matches the > **Note**
callout style already used in administration.md and dashboard.md.