Extract sigil-ansi: rewire monorepo consumers + boot pipeline

sigil-ansi now lives standalone at codeberg:sigil/sigil-ansi v0.13.1. Drop packages/sigil-ansi/ from the monorepo; rewire downstream consumers to pull via from-git pins; formalize sigil-build's previously-implicit dep declaration; extend the boot pipeline so the pre-sigil bootstrap fetches sigil-ansi alongside sigil-{lang,git,socket}.

Consumer rewires (from-workspace -> from-git): - packages/sigil-cli/package.sgl - packages/sigil-docs/package.sgl - packages/sigil-build/package.sgl: ADD an explicit (from-git url: "codeberg:sigil/sigil-ansi" version: "^0.13.1") entry. sigil-build/src/sigil/build.sgl, build/deps.sgl, and deps/fetch.sgl all import (sigil ansi); workspace co-residence had been masking the missing declaration.

Workspace bookkeeping: - Root package.sgl: drop "packages/sigil-ansi" from the workspace list; update the doc-comment with the new home. - Root dev-redirects.sgl: append codeberg:sigil/sigil-ansi -> ../task-extract-sigil-ansi/sigil-ansi (mirrors sigil-{lang,git,socket}).

Boot pipeline ((sigil ansi) is in BOOTSTRAPMODULES, so the boot make step needs .sigil/deps/sigil-ansi/src on disk before any sigil binary exists): - Makefile: ANSIPKG := .sigil/deps/sigil-ansi/src (was packages/sigil-ansi/src). Mirrors the SOCKETPKG / GITPKG pattern. Added a 5th preflight wildcard check for .sigil/deps/sigil-ansi/package.sgl. - scripts/ci-bootstrap-fetch-sigil-lang.sh: extend with a sigil-ansi section mirroring the sigil-git / sigil-socket blocks. Header comment updated to list sigil-ansi as the fourth bootstrap-required dep.

Lockfile bumps (alongside sigil-ansi auto-rewriting from legacy codeberg:sigil/sigil + selector route to standalone codeberg:sigil/sigil-ansi @ ffee474, the two consumers that had legacy sigil-ansi pins via the monorepo URL got patch-bumped on standalone-publish): - sigil-lsp 0.13.2 (541878f5) -> 0.13.3 (6c13dad3): dropped (sigil ansi) dep entirely (LSP server's JSON-RPC has no terminal coloring; help is plain text now). Refreshed sigil-stdlib pin to codeberg:sigil/sigil-lang. - sigil-repl 0.13.2 (9cfe9497) -> 0.13.3 (7b039ef4): re-pinned sigil-ansi to codeberg:sigil/sigil-ansi (kept the dep — terminal UI uses ansi extensively). Refreshed sigil-stdlib pin to codeberg:sigil/sigil-lang.

Validation (rewire dev binary built post-extraction, real-fetch deps): - Workspace test discovery: 978 passed / 0 failed (45 files). - Standalone sigil-ansi via rewire binary: 17/17 passed. - Spot-check: sigil eval '(begin (import (sigil ansi)) ...)' renders a:green output through the from-git pin.