docs(02-04): complete tier-2 inference platforms plan

Adds 02-04-SUMMARY.md; updates STATE.md and ROADMAP.md with execution metrics.
Completes PROV-02 (all 14 Tier 2 providers defined).

.planning/phases/02-tier-1-2-providers/02-04-SUMMARY.md

@@ -0,0 +1,114 @@
+---
+phase: 02-tier-1-2-providers
+plan: 04
+subsystem: providers
+tags: [providers, tier-2, inference-platforms, yaml]
+requires:
+  - pkg/providers/schema.go
+  - pkg/providers/loader.go
+  - pkg/providers/registry.go
+provides:
+  - providers/lepton.yaml
+  - providers/modal.yaml
+  - providers/cerebrium.yaml
+  - providers/novita.yaml
+  - providers/sambanova.yaml
+  - providers/octoai.yaml
+  - providers/friendli.yaml
+affects:
+  - pkg/providers/definitions/*.yaml (embed FS)
+tech_stack_added: []
+patterns:
+  - Generic-format providers rely on strong keyword lists for Aho-Corasick pre-filtering
+  - Dual-location copy (providers/ + pkg/providers/definitions/) maintained
+  - Medium-confidence prefixed regex for Modal (ak-/as-) and Friendli (flp_)
+  - Low-confidence fallback regex anchored by keywords for generic providers
+key_files_created:
+  - providers/lepton.yaml
+  - providers/modal.yaml
+  - providers/cerebrium.yaml
+  - providers/novita.yaml
+  - providers/sambanova.yaml
+  - providers/octoai.yaml
+  - providers/friendli.yaml
+  - pkg/providers/definitions/lepton.yaml
+  - pkg/providers/definitions/modal.yaml
+  - pkg/providers/definitions/cerebrium.yaml
+  - pkg/providers/definitions/novita.yaml
+  - pkg/providers/definitions/sambanova.yaml
+  - pkg/providers/definitions/octoai.yaml
+  - pkg/providers/definitions/friendli.yaml
+key_files_modified: []
+decisions:
+  - Modal defined with dual patterns (ak-/as-) — token_id and token_secret both needed for auth
+  - NovitaAI and SambaNova given live verify endpoints (OpenAI-compatible)
+  - Lepton, Cerebrium, OctoAI, Friendli left with empty verify stubs — no documented public models endpoint at research time
+  - Friendli promoted to medium confidence on flp_ prefix pattern
+metrics:
+  duration_seconds: 58
+  tasks_completed: 2
+  files_created: 14
+  completed: "2026-04-05"
+---
+
+# Phase 02 Plan 04: Tier 2 Inference Platforms (Generic Format) Summary
+
+Final 7 Tier 2 provider YAMLs (Lepton, Modal, Cerebrium, Novita, SambaNova, OctoAI, Friendli) added with keyword-anchored generic-format detection, completing PROV-02 (14/14 Tier 2 providers).
+
+## Objective
+
+Create the remaining 7 Tier 2 inference platform provider YAMLs that use generic-format key layouts (no distinctive prefix). Each requires a strong keyword list for Aho-Corasick pre-filtering so the low-confidence regex patterns do not fire indiscriminately.
+
+## Tasks Completed
+
+| Task | Name                                     | Commit  | Files |
+| ---- | ---------------------------------------- | ------- | ----- |
+| 1    | Lepton, Modal, Cerebrium, Novita YAMLs   | 622eabe | 8     |
+| 2    | SambaNova, OctoAI, Friendli YAMLs        | 5b5a47d | 6     |
+
+## Implementation Notes
+
+- **Modal** is the only dual-token provider in this batch — `MODAL_TOKEN_ID` (`ak-*`) and `MODAL_TOKEN_SECRET` (`as-*`) are both required for authentication. Both are emitted as medium-confidence patterns.
+- **Friendli** uses `flp_` prefix → medium-confidence primary pattern with a low-confidence fallback for older token formats.
+- **NovitaAI** and **SambaNova** expose OpenAI-compatible `/v1/models` endpoints and therefore have live verify specs ready for Phase 5 verification engine.
+- **Lepton**, **Cerebrium**, **OctoAI**, **Friendli** ship with empty verify stubs — their verification endpoints weren't resolved in research and will be filled in during Phase 5.
+- All 7 providers maintain tier: 2 and use lowercase keyword lists (lepton.ai, novita.ai, sambanova.ai, etc.) for AC matching.
+
+## Verification Results
+
+- `go test ./pkg/providers/... -count=1`: PASS (after task 1 and task 2)
+- Dual-location diffs empty for all 7 providers
+- Schema validation (UnmarshalYAML) passes for all files (format_version=1, last_verified set, valid confidences)
+
+## Deviations from Plan
+
+None - plan executed exactly as written.
+
+## Acceptance Criteria Status
+
+- [x] 7 generic-format Tier 2 providers created
+- [x] Dual-location verified (14 files, 7 in each location)
+- [x] Registry loads cleanly (go test passes)
+- [x] `grep -q 'MODAL_TOKEN_ID' providers/modal.yaml`
+- [x] `grep -q 'cerebrium.ai' providers/cerebrium.yaml`
+- [x] `grep -q 'api.novita.ai' providers/novita.yaml`
+- [x] `grep -q 'lepton.ai' providers/lepton.yaml`
+- [x] `grep -q 'sambanova' providers/sambanova.yaml`
+- [x] `grep -q 'octo.ai' providers/octoai.yaml`
+- [x] `grep -q 'FRIENDLI_TOKEN' providers/friendli.yaml`
+
+## Known Stubs
+
+The following providers have empty verify specs (method/url/status lists empty) and will require Phase 5 follow-up once verification endpoints are researched:
+
+- providers/lepton.yaml (verify.url empty)
+- providers/cerebrium.yaml (verify.url empty)
+- providers/octoai.yaml (verify.url empty)
+- providers/friendli.yaml (verify.url empty)
+- providers/modal.yaml (verify.url empty — Modal auth is non-trivial, uses token_id+token_secret pair)
+
+These are intentional per plan instructions (action block explicitly uses empty verify stubs for providers without documented public endpoints). Verification will be completed in Phase 5 (verification engine).
+
+## Self-Check: PASSED
+
+All 14 provider YAML files verified on disk. Both task commits (622eabe, 5b5a47d) present in git log.