… var placeholders

Extends scripts/generate-docs.ts to produce one MDX page per trigger
provider (39 pages) in apps/docs/content/docs/en/triggers/. The 5
hand-written pages (index, start, schedule, webhook, rss) are never
touched.

Key additions to the generation script:
- resolveConstVariable() resolves module-level const spreads so
  providers like Vercel that build outputs from const variables (not
  just functions) are fully documented
- resolveTriggerBuilderFunction() extended to expand variable spreads
  (...varName) in addition to function-call spreads (...fn())
- groupTriggersByProvider() deduplicates v1/v2 trigger variants by
  name, keeping the highest-versioned one per provider
- writeIconMapping() adds bare-name aliases for versioned block types
  (github_v2 → github, fireflies_v2 → fireflies, etc.) so
  BlockInfoCard resolves icons for all 39 trigger providers
- extractTriggerConfigFields() filters readOnly display blocks (webhook
  URL displays, sample payloads, curl examples) from config tables

Each generated page includes: BlockInfoCard with correct icon/color,
trigger count, polling note where applicable, Configuration table, and
Output table for every trigger. No "Type:" lines.

- Use ### `trigger_id` headings (matching ### `tool_id` in tools docs)
- Wrap all trigger sections under a ## Triggers header
- Rename Configuration/Output to #### level (matching #### Input/Output)
- Use Parameter column header to match tools docs table style
- Map UI widget types to semantic types: short-input/long-input/dropdown
  → string, switch → boolean, slider → number, oauth-input → string

Trigger IDs are internal identifiers; users scan by name. Switch from
### `trigger_id` to ### Trigger Name for cleaner sidebar navigation
and better readability.

…sections

Extends generate-docs.ts to parse subBlock builder functions so all 15
providers previously missing Configuration sections now generate them.

Handles three patterns:
- `buildTriggerSubBlocks({extraFields: buildX(...)})` — extracts extra
  fields from the call site and resolves them from the provider's utils.ts
- `return [...]` — direct array return (Attio, Confluence, etc.)
- `blocks.push(...)` — imperative push pattern (Linear, Ashby)

Also resolves const-reference field IDs (SCREAMING_CASE) by searching
the webhook provider constants cache, fixing Gong's `gongJwtPublicKeyPem`
field which was previously unresolvable. Adds title-as-description fallback
for OAuth credential fields that have no explicit description.

Fixes a parser bug where output fields with no top-level `type` key but
child fields each having their own `type`/`description` were incorrectly
parsed. The `type:` and `description:` regex matches were not
depth-aware, so values from nested children bled into the parent field.

Changes:
- Add `isAtDepthZero()` helper for brace-depth-aware regex matching
- Fix `parseFieldContent` to only match `type:` at brace depth 0
- Fix `extractDescription` to only match `description:` at brace depth 0
- Add implicit-object fallback: when no top-level `type` exists but child
  fields have their own types, treat as `object` with `properties`
- Regenerate all affected trigger docs (Cal.com payload, Linear data,
  Jira issue.fields, Ashby application, Greenhouse candidate, etc.)