MarkdownHelp: page-context awareness + backfill missing directives

Current state

MarkdownHelp.vue (client/src/components/Markdown/MarkdownHelp.vue) is a single hand-written component with a binary mode: DirectiveMode prop where DirectiveMode = "page" | "report" (client/src/components/Markdown/directives.ts:3). It is mounted in exactly one place — the GModal inside MarkdownEditor.vue (client/src/components/Markdown/MarkdownEditor.vue:38-44) — and the title flips on the same boolean ("Markdown Help for Pages" vs "Markdown Help for Invocation Reports"). Two callers drive the prop: PageEditorView.vue:61 hard-codes markdownEditorMode = "page" for both standalone and history-attached pages, and Workflow/Editor/Index.vue:125 hard-codes mode="report". So after the notebooks/reports unification, “history page” and “standalone page” collapse to the same mode="page" help — exactly the original concern. The history-page assistant context is never wired in.

The PR-era diff (git log 4afd63a9a9 -- client/src/components/Markdown/MarkdownHelp.vue) only changed a type import and one wording tweak (“resulting Galaxy Page” → “resulting document”). Help content is otherwise inherited unchanged from the pre-unification era and has not absorbed history-context knowledge.

Concrete gaps

DirectiveMode has only two values; there is no third “history” arm, so the help cannot say “you’re editing a page attached to a history” vs “standalone page that references arbitrary histories by ID” (directives.ts:3, PageEditorView.vue:48,61).
MarkdownHelp.vue:51-55 tells all page users “These elements are referenced by object IDs used by the Galaxy API” — fine for standalone pages but misleading for history-attached pages where the assistant resolves HIDs to IDs (see lib/galaxy/agents/prompts/page_assistant.md:7-27); user-facing help never mentions HIDs, resolve_hid, or the AI chat panel.
Help omits a large chunk of valid directives — MarkdownHelp.vue documents 14 directives but VALID_ARGUMENTS in lib/galaxy/managers/markdown_parse.py:26-70 exposes ~30. Missing from the help: history_dataset_embedded, history_dataset_index, history_dataset_link, history_dataset_name, history_dataset_type, history_link, invocation_inputs, invocation_outputs, visualization, generate_time, generate_galaxy_version, and all seven instance_*_link directives. Most are documented in the rich tables in lib/galaxy/agents/prompts/page_assistant.md:92-135 — so the AI knows about them but the human help does not.
Inline directive syntax (${galaxy history_dataset_name(...)}) — promoted heavily in lib/galaxy/agents/prompts/page_assistant.md:62,85,104,141 and gated on EMBED_CAPABLE_DIRECTIVES (lib/galaxy/managers/markdown_parse.py:71-86) — is not mentioned anywhere in MarkdownHelp.vue (zero matches for ${galaxy or “inline”).
workflow_display(workflow_id=33b43b4e7093c91f>) at MarkdownHelp.vue:110 has a stray > — typo that ships to users.
The directives.yml metadata already supports per-mode strings via directiveEntry() in directives.ts:25-64 and %MODE% substitution — but no entry uses a third “history” key because the type doesn’t allow it.

Recommended follow-up

Widen DirectiveMode and thread real context through (S). Files: directives.ts, MarkdownHelp.vue, MarkdownEditor.vue, PageEditorView.vue, directives.yml. Change DirectiveMode to "page_standalone" | "page_history" | "report" or keep "page" and add a sibling historyAttached: boolean prop (less churn). PageEditorView.vue:61 already knows via editorMode / isStandalone; pass that through. directiveEntry() already does per-mode lookup so YAML additions are localized.
Backfill missing directives in the help (S). Files: MarkdownHelp.vue, directives.yml. Drive the DirectiveHelpSection directive lists from VALID_ARGUMENTS (or a curated subset) instead of three hand-written arrays. At minimum add inline-capable directives (history_dataset_name, history_dataset_type, workflow_license, generate_time, generate_galaxy_version, instance_*), history_dataset_embedded, history_dataset_index, history_dataset_link, invocation_inputs, invocation_outputs, history_link, visualization. Mark inline-capable ones with a badge fed by EMBED_CAPABLE_DIRECTIVES.
Document inline syntax and HID/ID resolution for history pages (XS). Files: MarkdownHelp.vue, directives.yml. Add a short “Inline references” section with a ${galaxy history_dataset_name(history_dataset_id=...)} example, and — when context is history-attached — a short blurb that the AI chat panel can resolve HIDs and pick IDs for you. Reuse phrasing from lib/galaxy/agents/prompts/page_assistant.md:55-68.
Single source of truth for directive metadata (M, out of scope for this issue). Move the directive catalog (name, description, help, embed-capable, valid args) into a server-served JSON sourced from markdown_parse.py, so directives.yml, MarkdownToolBox, MarkdownHelp, and the agent prompt cannot drift. Real tech debt; punt until there’s a second drift incident.

Also: fix the stray > typo at MarkdownHelp.vue:110 while you’re in there.

Scope for this issue

Items 1 + 2 + 3 + typo. Probably an afternoon. Item 4 is mentioned as out-of-scope for future work.

References