Docs/Project: duplicate 'BanyanLabs Dogfood(ing)' Initiative option and inconsistent Area/Initiative framing

[codeforester]

Goal

Remove the near-duplicate "Initiative" Project field option and reconcile
docs/github-workflow.md's two conflicting descriptions of how Area/
Initiative option lists are defined.

Background

A documentation review of the process/workflow docs, cross-checked against
the live GitHub Project (basefoundry/base, project #10), found:

• The Project's actual "Initiative" field currently has two near-duplicate
  options: BanyanLabs Dogfood and BanyanLabs Dogfooding (confirmed via
  gh project field-list 10 --owner basefoundry), with no indication which
  is canonical. docs/github-workflow.md:116-117 and
  .github/base-project.yml:16-17 both faithfully reproduce this duplicate
  in their option lists rather than catching it as a bug.
• docs/github-workflow.md:113-118 gives Area/Initiative as fixed,
  concrete option lists in the "Issue Project Metadata" section, but the same
  document's later "Projects" section (:730-732) describes them instead as
  "repo-specific options declared in .github/base-project.yml," with no
  cross-link connecting the two framings — a reader can't tell whether the
  list in front of them is authoritative or just an example.

Scope

• .github/base-project.yml
• The live GitHub Project "Initiative" field options (project Reorganize Base libraries under a top-level lib tree #10, owner
  basefoundry)
• docs/github-workflow.md

Acceptance Criteria

• The live Project's "Initiative" field has a single canonical entry for
  the BanyanLabs dogfooding work (either BanyanLabs Dogfood or
  BanyanLabs Dogfooding, not both), and any existing items using the
  removed option are migrated first.
• .github/base-project.yml matches the reconciled option list.
• docs/github-workflow.md:113-118 and :730-732 are reconciled so it's
  clear in one place whether the Area/Initiative lists shown are
  authoritative or .github/base-project.yml is the single source of
  truth (with the other section linking to it instead of restating it).

Validation

gh project field-list 10 --owner basefoundry --format json after the
change, confirming a single BanyanLabs-dogfooding option; git diff --check
on the doc changes.

Non-Goals

• Renaming or restructuring other Project fields beyond the Initiative
  duplicate.

Project Metadata

• Priority: P2
• Size: S
• Area: Docs
• Initiative: Adoption Polish
• Agent Assignment: Human first (touches live GitHub Project configuration,
  not just doc text — needs a human to confirm no in-flight items use the
  option being removed before deleting it)