feat(forms): add question management and watch commands

[alexknowshtml]

Summary

Extends the forms command group (added in v0.11.0) with full question management and response watch capabilities, covering the remaining Google Forms API surface.

New Commands

Question management (via forms.batchUpdate):

• forms add-question — Add text, paragraph, radio, checkbox, dropdown, scale, date, or time questions with --type, --option, --required, --index, and type-specific flags
• forms update — Modify form title, description, or quiz mode after creation
• forms delete-question — Remove a question by index
• forms move-question — Reorder questions

Response watches (push notifications):

• forms watch create — Subscribe to response notifications via Cloud Pub/Sub
• forms watch list — List active watches
• forms watch delete — Remove a watch
• forms watch renew — Extend a watch (7-day expiry)

Usage Examples

# Add a required paragraph question
gog forms add-question <formId> --title "Describe the issue" --type paragraph --required

# Add a multiple choice question
gog forms add-question <formId> --title "Category" --type radio \
  -o "Bug report" -o "Feature request" -o "Other"

# Add a linear scale
gog forms add-question <formId> --title "How satisfied are you?" --type scale \
  --scale-low 1 --scale-high 10 --scale-low-label "Not at all" --scale-high-label "Very"

# Update form metadata
gog forms update <formId> --title "New Title" --description "Updated description"

# Enable quiz mode
gog forms update <formId> --quiz true

# Delete question at index 2
gog forms delete-question <formId> 2

# Reorder: move question from position 3 to position 0
gog forms move-question <formId> 3 0

# Watch for new responses
gog forms watch create <formId> --topic "projects/my-project/topics/my-topic"
gog forms watch list <formId>
gog forms watch renew <formId> <watchId>

Implementation Notes

• All commands follow existing patterns: --json/--plain output, --dry-run support, --force for destructive ops
• Uses ForceSendFields on Location.Index to correctly handle index 0 (Go zero-value)
• add-question with default --index=-1 fetches current form to determine append position
• Question type flags are scoped (scale flags only relevant for --type scale, etc.)

Files Changed

• internal/cmd/forms.go — Wired 6 new subcommands into FormsCmd struct
• internal/cmd/forms_modify.go — Question CRUD + form update commands (426 lines)
• internal/cmd/forms_watch.go — Watch lifecycle commands (241 lines)

Test Plan

• Existing forms tests pass (TestExecute_FormsGet_Text, TestExecute_FormsResponsesList_JSON, etc.)
• go build ./... compiles cleanly
• All 8 new commands show in gog forms --help
• Smoke tested add-question against a live form (6 questions of various types)
• Smoke tested update to modify form description
• Unit tests for new commands (happy to add if desired)

[steipete]

Landed directly on main after deep review and fixup.

PR head repo is no longer available, so the rebased branch could not be pushed back for a normal PR merge.

• Gate: make ci
• Land commits: 1de2305, 5c3eaa4, 2d38040

Key fixups:

• added delete-question validation + confirmation guardrails
• added focused tests for question building, add/delete flows, and watch commands
• updated README and CHANGELOG

Thanks @alexknowshtml!

[steipete]

Closed after direct landing on main; see landed commits and tests above.