fix(calendar): surface degraded get_calendar_events sentinel so web fallback fires

[Copilot]

Analysis of the last 5 agentic-workflow PRs (#2819, #2821, #2822, #2823, #2824) for degraded datasources surfaced a client masking bug: when data.riksdagen.se/kalender/ serves an HTML error page, the riksdag-regering MCP get_calendar_events tool returns a successful result wrapping a sentinel {count:0, events:[], error, rawHtml}. The clients read the empty events:[] as a legitimate zero-event window, so scripts/calendar-fetch.ts reported a false status:ok, path:mcp-primary and the web-scraper fallback never fired — masking the outage as a real zero-sitting week.

Client code

• scripts/fetch-calendar/mcp/errors.ts — new isDegradedKalenderSentinel() detector; triggers only on a non-empty error string or rawHtml, so a clean {count:0, events:[]} stays a valid empty window.
• scripts/fetch-calendar/mcp/client.ts — detect the sentinel in both the content-wrapped and direct-result paths and throw CalendarMcpError(..., 'html', rawHtml); orchestrator.ts already breaks the retry loop on kind:'html' and falls straight to the public-page scraper.
• scripts/mcp-client/methods/calendar.ts — mirror the detection (throw instead of returning []).
• scripts/fetch-calendar.ts — re-export the new detector.

if (isDegradedKalenderSentinel(inner)) {
  throw new CalendarMcpError(
    `MCP kalender API degraded: ${String(inner['error'] ?? 'upstream HTML error')}`,
    'html',
    typeof inner['rawHtml'] === 'string' ? inner['rawHtml'] : undefined,
  );
}

With the fix, the CLI now reports status:error, path:none during the outage instead of a fabricated zero-event success.

Agentic config / prompts / instructions

• analysis/templates/session-baseline.md — added a 📅 Calendar sourcing degraded-source guard and pointed the 3 inline get_calendar_events references at the resilient data/runtime/calendar-status.json / scripts/calendar-fetch.ts.
• .github/prompts/02-mcp-access.md — added a data-sourcing rule: fetch the calendar via the resilient CLI / pre-warm artifact (never the raw tool); record [DATA GAP: calendar source degraded] when both paths fail.

Tests

• Regression coverage across tests/fetch-calendar/mcp/errors.test.ts, tests/fetch-calendar/mcp/client.test.ts (content + direct sentinel → kind:'html'), tests/fetch-calendar/orchestrator-integration.test.ts (sentinel → web-fallback), and tests/mcp-client/methods/calendar.test.ts (sentinel → throws).

Out of scope (documented)

The public fallback page moved from /sv/kalendarium/ (now 404) to a Next.js /sv/aktuellt/kalendersida/ serving data in __NEXT_DATA__; repointing the HTML scraper needs a parser rewrite plus markup fixtures. The now-honest status:error/path:none ensures the degradation is no longer silently masked in the meantime.

IMF (no change)

The other degraded source flagged in the manifests is already mitigated by the 3-tier WEO pipeline and data/imf-context.json degraded/unavailable handling.

[github-actions]

🏷️ Automatic Labeling Summary

This PR has been automatically labeled based on the files changed and PR metadata.

Applied Labels: documentation,testing,refactor,size-m

Label Categories

• 🗳️ Content: news, dashboard, visualization, intelligence
• 💻 Technology: html-css, javascript, workflow, security
• 📊 Data: cia-data, riksdag-data, data-pipeline, schema
• 🌍 I18n: i18n, translation, rtl
• 🔒 ISMS: isms, iso-27001, nist-csf, cis-controls
• 🏗️ Infrastructure: ci-cd, deployment, performance, monitoring
• 🔄 Quality: testing, accessibility, documentation, refactor
• 🤖 AI: agent, skill, agentic-workflow

For more information, see .github/labeler.yml.

[github-actions]

🔍 Lighthouse Performance Audit

Category	Score	Status
Performance	85/100	🟡
Accessibility	95/100	🟢
Best Practices	90/100	🟢
SEO	95/100	🟢

📥 Download full Lighthouse report

Budget Compliance: Performance budgets enforced via budget.json

[pethers]

@copilot analyse

TypeScript & JavaScript Testing / Build Test (Vite) (pull_request)
TypeScript & JavaScript Testing / Build Test (Vite) (pull_request)Failing after 11m

and improve code quality and test coverage

[Copilot]

@copilot analyse

TypeScript & JavaScript Testing / Build Test (Vite) (pull_request)
...

The CI failure was a runner timeout/shutdown during the prebuild step (render-articles.ts --all --lang all rendering 237 articles × 14 languages) — not related to the calendar code changes.

I've made the following improvements in commit c22ecda:

Code quality:

• Refactored scripts/mcp-client/methods/calendar.ts to import and reuse the shared isDegradedKalenderSentinel() function instead of duplicating the detection logic inline.

Test coverage (50 → 59 tests, all passing):

• errors.test.ts: both error + rawHtml present, rawHtml-only sentinel, empty object, additional non-string type variants (undefined, true, [])
• client.test.ts: malformed JSON content → kind:'json', rawHtml propagation to responseText, error message propagation in thrown error, rawHtml-only sentinel without error field
• calendar.test.ts: rawHtml-only sentinel (no error field), error message verification in thrown error

[github-actions]

🔍 Lighthouse Performance Audit

Category	Score	Status
Performance	85/100	🟡
Accessibility	95/100	🟢
Best Practices	90/100	🟢
SEO	95/100	🟢

📥 Download full Lighthouse report

Budget Compliance: Performance budgets enforced via budget.json

[Copilot]

Pull request overview

This PR fixes calendar outage handling so degraded get_calendar_events MCP responses are surfaced as failures instead of being interpreted as legitimate empty calendars, allowing fallback/error reporting paths to behave honestly.

Changes:

• Adds degraded calendar sentinel detection for error/rawHtml MCP payloads.
• Wires detection into both the resilient calendar fetcher and generic MCP calendar method.
• Updates prompt/template guidance and adds regression tests for sentinel handling and fallback behavior.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
scripts/fetch-calendar/mcp/errors.ts	Adds isDegradedKalenderSentinel() detector.
scripts/fetch-calendar/mcp/client.ts	Throws CalendarMcpError('html') for degraded sentinel payloads.
scripts/fetch-calendar.ts	Re-exports the new detector.
scripts/mcp-client/methods/calendar.ts	Makes generic MCP calendar calls throw on degraded sentinel results.
tests/fetch-calendar/mcp/errors.test.ts	Covers sentinel detection positives and negatives.
tests/fetch-calendar/mcp/client.test.ts	Covers content-wrapped/direct sentinel handling and error propagation.
tests/fetch-calendar/orchestrator-integration.test.ts	Verifies sentinel-triggered web fallback.
tests/mcp-client/methods/calendar.test.ts	Covers generic MCP client sentinel failures.
analysis/templates/session-baseline.md	Documents resilient calendar sourcing guidance.
.github/prompts/02-mcp-access.md	Instructs workflows to use the resilient CLI/prewarm artifact instead of raw calendar tool output.