feat(0.2): Align pillar foundation — repos.yaml + alignment-first migration + tier badges (Tracks 6.1/6.5/6.6)

[pmclSF]

Summary

Three Track 6 deliverables that establish the Align pillar's 0.2.0
foundation. Track 6 is intentionally parallel and partial-ship-OK
(Align is the secondary pillar; floor ≥ 3 soft per the parity
plan); this PR lands the parts that lift Align without requiring
the full multi-repo aggregator. The aggregator (Tracks 6.2 / 6.3)
lands in 0.2.x once the manifest format ships here.

• Track 6.1 — Multi-repo manifest format. New
  internal/portfolio/manifest.go defines the
  .terrain/repos.yaml schema (version-pinned to 1) with
  per-repo path or pre-saved snapshot, optional owner,
  frameworks-of-record declaration, tags. Loader + validator +
  path resolution helpers ready for the aggregator.
• Track 6.5 — Migration alignment-first reframe. New
  docs/product/alignment-first-migration.md documents the
  framing shift: declare a framework of record per repo, see
  drift, converge gradually. Conversion is one tool inside
  convergence, not the headline.
• Track 6.6 — Per-direction tier badges in migrate list.
  terrain migrate list and terrain migrate shorthands now
  surface Tier vocabulary (Stable / Experimental / Preview /
  Cataloged) instead of raw GoNativeState strings.

Test plan

• go build ./... clean
• go test ./internal/portfolio/... — 12 new manifest tests
  (canonical + every validation rule + path resolution variants)
• go test ./cmd/terrain/... — new tier label test + existing
  smoke tests pass
• make docs-verify passes
• Manual smoke: terrain migrate list renders the new tier
  badges (separate verification — needs a built binary)

Plan tracker

Closes Track 6.1, 6.5, 6.6. Track 6 remaining (post-0.2.0 or
0.2.x): 6.2 per-repo snapshot ingestion + 6.3 cross-repo
aggregator + 6.4 multi-repo example fixture + 6.7 conversion-
corpus calibration to A-grade. Per the plan, those are partial-
ship-OK; the manifest format ships in 0.2.0 with Tier 3 /
experimental marketing on multi-repo until 6.2/6.3 land.

🤖 Generated with Claude Code

[github-actions]

Terrain AI Risk Review

Metric	Value
AI surfaces	13
Eval scenarios	16
Impacted scenarios	0
Uncovered surfaces	13

Decision: PASS — AI surfaces are covered.

[github-actions]

[RISK] Terrain — Merge with caution

High-severity gaps found in changed code.

Metric	Value
Changed files	5 (2 source · 2 test)
Impacted units	8
Protection gaps	2
Tests selected	2 of 774 (0% of suite)

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Coverage gaps in changed code

• cmd/terrain/cmd_convert.go [MED] — Exported function Error has no observed test coverage.
  → Add unit tests for exported function Error — this is public API surface.
• internal/portfolio/manifest.go [MED] — Exported function RepoManifest has no observed test coverage.
  → Add unit tests for exported function RepoManifest — this is public API surface.

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Pre-existing issues (2)

• cmd/terrain/cmd_convert.go [HIGH] — [blastRadiusHotspot] Changes to this file propagate to 163 tests (163 direct, 0 indirect). High blast radius increases regression risk.
• internal/portfolio/manifest.go [HIGH] — [blastRadiusHotspot] Changes to this file propagate to 1657 tests (85 direct, 1572 indirect). High blast radius increases regression risk.

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Recommended tests

2 test(s) with exact coverage of 5 impacted unit(s). 3 impacted unit(s) have no covering tests in the selected set.

Test	Confidence	Why
cmd/terrain/cmd_convert_tier_test.go	exact	test file directly changed
internal/portfolio/manifest_test.go	exact	exact coverage of LoadRepoManifest, ParseRepoManifest, RepoEntry + 2 more

---

Owners: PMCLSF

Limitations

• No coverage artifacts provided; protection gaps reflect missing data, not measured absence. Provide --coverage to improve accuracy.
• Mixed test cultures reduce cross-framework optimization confidence. Consider standardizing on fewer frameworks.

_{Generated by Terrain · terrain pr --json for machine-readable output}

Targeted Test Results

Terrain selected 2 test(s) instead of the full suite.

• Go tests: passed