[279] feat: wire Bitbucket Pipelines into parsec ci + pr-status mapping

[erishforG]

Summary

Closes the two gaps left after the Bitbucket Cloud forge work in #240 (PR #276):

1. `parsec ci` now dispatches on the origin remote

When the remote is Bitbucket, `ci` resolves the PR's source branch and polls the Pipelines API (`/repositories/.../pipelines/`) instead of GitHub Checks. The result is shaped into the existing `CiStatus` struct so renderers, `--watch`, and exit-code logic stay forge-agnostic.

2. `parsec pr-status` Bitbucket branch returns real CI / review

No more hardcoded `"unknown"` for `ci_status` / `review_status`:

• `ci_status` ← latest pipeline for the PR's source branch
• `review_status` ← PR participants list

Both fall back to `"unknown"` on network error rather than failing the whole command.

Vocabulary matches the GitHub path exactly:

• CI: `passing` | `failing` | `pending` | `no checks` | `unknown`
• Review: `approved` | `changes_requested` | `pending` | `no reviews`

Closes #279

Changes

• `src/cli/commands/ci.rs` — remote-aware dispatch + Bitbucket Pipelines path with `--watch` support.
• `src/cli/commands/pr.rs` — fill CI/review for Bitbucket pr-status.
• `src/bitbucket/mod.rs` — new helpers: `get_latest_pipeline_for_branch`, `get_pr_source_branch`, `get_pr_participants`. Pure mapping fns `pipeline_to_ci_status` / `participants_to_review_status` are unit-tested directly.
• `src/env.rs` — `PARSEC_BITBUCKET_API_BASE` env var so tests can point at a mock server (also useful for future Bitbucket Server / Data Center support).
• `Cargo.toml` — `mockito` as dev-dependency. The codebase had no HTTP mocking infra and the new integration tests need it. Justified in commit message.
• `tests/bitbucket_integration_tests.rs` (new) — 5 integration tests.

GitHub repo behaviour is unchanged — verified by the unchanged 40 existing integration tests + an explicit `expect(0)` assertion on `/repos/*` in the Bitbucket CI integration test (catches dispatch regressions).

Verification

Check	Result
`cargo build --release`	✅
`cargo test`	✅ 76 passed (31 unit + 5 new integration + 40 existing)
`cargo clippy --all-targets -- -D warnings`	✅ clean
`cargo fmt -- --check`	✅ clean

Test plan

• CI green
• Manual: against a real Bitbucket repo, `parsec ci ` shows live pipeline status
• Manual: `parsec pr-status` shows CI + review state instead of `unknown`
• Regression: GitHub repos behave unchanged (CI calls Checks API, pr-status reads gh fields)