#3017 extension push output: double-quoted adjacent interpolations, repo-relative paths, and --json emits three JSON documents

Problem

Three presentation defects in swamp extension push output, all in the CLI renderer (src/cli/commands/extension_push.ts renderer :97, :113, :128, :283):

1. Two values are interpolated back to back (${arg.type}${opt}), which LogTape quotes separately, so the log prints "string"" (optional)" and "...work-item-summary"" [method]". AGENTS.md already names this pitfall.
2. File names are printed relative to --repo-dir, so a manifest outside the repo shows as ../../.cue/work/... instead of a path the author can open.
3. --json --dry-run emits three separate pretty-printed JSON documents (resolved data with the review skeleton inlined as an escaped string, then warnings, then status), so JSON.parse of the output fails and jq -s is needed.

Expected

• One interpolation per LogTape value.
• Paths relative to the current directory (or absolute when outside it).
• --json emits one JSON object with resolved, warnings and status as fields; the review skeleton is a nested object, not an escaped string.

Acceptance

• push --dry-run log output contains no "" sequences from adjacent interpolations.
• push --dry-run --json manifest.yaml | jq .status works without -s.
• A manifest at ../other/manifest.yaml is printed as that, not relative to the repo dir.

Out of scope

Prompt wording and flags are #2939 and the --accept-warnings issue in the same lane.

Source: the extension push assessment (2026-10-02, swamp 20261002.194016) and the Extension Push UX Plan, which groups this with its lane and order.