Auto-refresh KB pricing, align skill with Anthropic best practices

Why this set of changes:
- KB pricing was drifting silently — domain files (database.yaml,
  storage.yaml, etc.) had prices 30-800% off the live Oracle API and
  nobody read them. The skill was auditing as stale on every check
  with no path to fix it.
- The skill itself violated Anthropic's spec (`name` field had
  uppercase/spaces) and was over the 500-line guideline (647 lines),
  hurting discovery and load performance.
- Welcome flow occasionally improvised the menu instead of reading
  SKILL.md, missing options.

Pricing — single source of truth, fully automated:
- Extend tools/refresh_sku_catalog.py with --refresh-domain compute,
  pulls shape-level prices from the Oracle public pricing API
  (apexapps.oracle.com), preserves manual fields (notes, GPU specs,
  free-tier annotations, estimation_helpers), recomputes derived
  monthly values, and protects $0 free-tier prices from overwrite.
- Delete 12 redundant pricing/<domain>.yaml files. They duplicated
  oci-sku-catalog.yaml with worse abstractions and were nobody's
  source of truth (no tool consumed them).
- Migrate the genuinely valuable knowledge from those 12 files
  (billing models, BYOL rules, free-tier rules, ECPU vs OCPU,
  X11M elastic model, hyperscaler comparisons, service nuances)
  into kb/field-knowledge/pricing-knowledge.yaml — non-numeric,
  no refresh needed.
- Result: pricing freshness check goes from 13 stale files to 0.

KB freshness automation:
- Add tools/kb_freshness.py — wrapper around kb_linter.check_freshness()
  with --check, --auto-refresh, --json, --quiet modes. Bridges stale
  files to their refresh tools (SKU catalog, compute domain, arch
  center). Wired into the welcome flow as a pre-flight banner that
  asks the user before refreshing.
- Fix pre-existing kb_linter bug: it crashed on the 45 multi-doc
  YAML files (frontmatter + body pattern) because it used safe_load
  instead of safe_load_all. Freshness check was effectively dead.
- Standardize timestamp field: linter now accepts last_verified,
  last_updated, and last_refreshed; refresh_arch_catalog writes
  last_verified instead of last_refreshed.
- Add make freshness / make freshness-refresh targets.

Skill alignment with Anthropic Agent Skills best practices:
- Rename `name: OCI Deal Accelerator` to `oci-deal-accelerator`
  to comply with the [a-z0-9-]{1,64} spec.
- Refactor SKILL.md from 674 to 445 lines via progressive disclosure:
  extract WA review output format, ECAL readiness format, and output
  conventions into docs/skill/*.md referenced from the main file.
- Add scripts/sync-skill.py + make sync-skill: source of truth is
  root SKILL.md, .agents/skills/oci-deal-accelerator/SKILL.md is
  auto-generated. make lint validates sync.
- Add evaluations/ with 3 manual baseline scenarios (welcome-flow,
  full-proposal, wa-review) per the Anthropic best-practices guidance
  to "build evaluations first."

Welcome flow hardening:
- Tighten CLAUDE.md to MANDATE reading SKILL.md before showing the
  menu (no improvising), and document the freshness pre-flight check
  with the ask-before-refresh user flow.
- Update SKILL.md welcome flow to instruct: parse kb_freshness JSON,
  show banner with stale count + oldest file, prompt user to refresh
  (only when an automated tool exists), fall back silently on errors.

Linter hygiene (zero remaining issues):
- Expand config/kb-tags.yaml taxonomy with features, operations,
  metrics, limitations sections covering 31 previously-unknown tags
  used in field findings (rac, ecpu, refreshable-clone, hnsw, etc.).
- Assign owners for kb/compatibility/, kb/competitive/,
  kb/well-architected/ (Diego Cabrera as default until team grows);
  kb/pricing/ marked as "Auto-refreshed" since it no longer needs
  human ownership.
- kb_linter accepts top-level `date` as fallback for contributor
  block; migrate FF-202603-008 from legacy `reported_by` to
  contributor block.
- Result: linter goes from 45 issues to 0.

Other:
- Recompute estimation_helpers monthly values in compute.yaml after
  the price refresh (they were derived from the old E5/A1 numbers).
- Add kb/README.md — contributor guide (directory map, frontmatter
  spec, refresh tooling, review cadence).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tools/kb_linter.py

@@ -60,7 +60,14 @@ def _load_yaml(path: str) -> Optional[Dict[str, Any]]:
     if not os.path.isfile(resolved):
         return None
     with open(resolved, "r", encoding="utf-8") as fh:
-        return yaml.safe_load(fh)
+        # Many KB files use a frontmatter pattern: a metadata doc followed by
+        # a body doc, separated by `---`. Merge all dict docs into one so
+        # callers see a single namespace (later docs override earlier keys).
+        merged: Dict[str, Any] = {}
+        for doc in yaml.safe_load_all(fh):
+            if isinstance(doc, dict):
+                merged.update(doc)
+        return merged or None
 
 
 def _load_governance() -> Dict[str, Any]:
@@ -125,8 +132,14 @@ def check_contributor_blocks(tracker_path: str = TRACKER_PATH) -> List[str]:
             else:
                 issues.append(f"{fid}: missing contributor block")
             continue
+        # The finding's top-level `date` is the canonical discovery date and
+        # acts as a fallback when the contributor block doesn't repeat it.
+        finding_date = f.get("date")
         for field in required:
-            if not contributor.get(field):
+            value = contributor.get(field)
+            if not value and field == "date" and finding_date:
+                continue
+            if not value:
                 issues.append(f"{fid}: contributor missing required field '{field}'")
         conf = contributor.get("confidence", "")
         if conf and conf not in valid_confidence:
@@ -239,7 +252,11 @@ def check_freshness() -> List[Dict[str, Any]]:
             if not data:
                 continue
 
-            last_verified = data.get("last_verified") or data.get("last_updated")
+            last_verified = (
+                data.get("last_verified")
+                or data.get("last_updated")
+                or data.get("last_refreshed")
+            )
             if last_verified:
                 age = _days_ago(last_verified)
                 if age is not None: