feat(pricing): add Bedrock rows for Opus 4.8/4.7, correct Opus 4.6 to $5/$25

Adds current-gen Claude Opus pricing rows on Bedrock keyed to Anthropic's
published list price, which commercial Bedrock on-demand mirrors. Also
corrects the existing Opus 4.6 row: it carried Claude-3-era Opus pricing
($15/$75); Opus 4.5+ list at $5/$25 with cache write 1.25x / read 0.1x.

The AWS Price List API had not published these SKUs machine-readably as
of 2026-07, so these are commercial-list snapshots pending an
authoritative machine source.

Reapplied from PR #62327 (commit authored under a placeholder identity,
so cherry-pick was not usable; sonnet-5 row from that PR already landed
via #67932).

Co-authored-by: pgregg88 <4943027+pgregg88@users.noreply.github.com>

agent/usage_pricing.py

@@ -545,17 +545,47 @@ _OFFICIAL_DOCS_PRICING: Dict[tuple[str, str], PricingEntry] = {
     # Bedrock charges the same per-token rates as the model provider but
     # through AWS billing.  These are the on-demand prices (no commitment).
     # Source: https://aws.amazon.com/bedrock/pricing/
+    # Current-gen Claude Opus on Bedrock. Commercial Bedrock on-demand
+    # mirrors Anthropic's published list price for the Claude line
+    # ($5/$25 for Opus 4.6/4.7/4.8; cache write = 1.25x input at the
+    # 5-minute TTL, cache read = 0.1x input). NOTE: the AWS Price List API
+    # had not published these SKUs machine-readably as of 2026-07 — these
+    # are commercial-list snapshots pending an authoritative machine source.
+    (
+        "bedrock",
+        "anthropic.claude-opus-4-8",
+    ): PricingEntry(
+        input_cost_per_million=Decimal("5.00"),
+        output_cost_per_million=Decimal("25.00"),
+        cache_read_cost_per_million=Decimal("0.50"),
+        cache_write_cost_per_million=Decimal("6.25"),
+        source="official_docs_snapshot",
+        source_url="https://aws.amazon.com/bedrock/pricing/",
+        pricing_version="anthropic-list-2026-07",
+    ),
+    (
+        "bedrock",
+        "anthropic.claude-opus-4-7",
+    ): PricingEntry(
+        input_cost_per_million=Decimal("5.00"),
+        output_cost_per_million=Decimal("25.00"),
+        cache_read_cost_per_million=Decimal("0.50"),
+        cache_write_cost_per_million=Decimal("6.25"),
+        source="official_docs_snapshot",
+        source_url="https://aws.amazon.com/bedrock/pricing/",
+        pricing_version="anthropic-list-2026-07",
+    ),
     (
         "bedrock",
         "anthropic.claude-opus-4-6",
     ): PricingEntry(
-        input_cost_per_million=Decimal("15.00"),
-        output_cost_per_million=Decimal("75.00"),
-        cache_read_cost_per_million=Decimal("1.50"),
-        cache_write_cost_per_million=Decimal("18.75"),
+        input_cost_per_million=Decimal("5.00"),
+        output_cost_per_million=Decimal("25.00"),
+        cache_read_cost_per_million=Decimal("0.50"),
+        cache_write_cost_per_million=Decimal("6.25"),
         source="official_docs_snapshot",
         source_url="https://aws.amazon.com/bedrock/pricing/",
-        pricing_version="bedrock-pricing-2026-04",
+        pricing_version="anthropic-list-2026-07",
     ),
     (
         "bedrock",

tests/agent/test_usage_pricing.py

@@ -348,6 +348,43 @@ def test_bedrock_claude_rows_all_carry_cache_pricing():
         assert entry.cache_write_cost_per_million > entry.input_cost_per_million, key
 
 
+def test_bedrock_current_gen_claude_rows_resolve():
+    """Current-gen Claude models (Opus 4.8/4.7, Sonnet 5) must have Bedrock
+    pricing rows so cached sessions report a dollar cost, not ``unknown``.
+    Assert each resolves via the bare id and a cross-region inference profile
+    (us./global. prefix), that every id for a given model resolves to the same
+    entry, and that the row carries the cache fields a Bedrock Claude session
+    needs.
+
+    (Version-suffixed IDs like ``...-v1:0`` are covered separately by the
+    normalizer test in the suffix-strip change; this test intentionally sticks
+    to id shapes that resolve on ``main`` so it is independent of that PR.)
+    """
+    url = "https://bedrock-runtime.us-east-1.amazonaws.com"
+    for bare in (
+        "anthropic.claude-opus-4-8",
+        "anthropic.claude-opus-4-7",
+        "anthropic.claude-sonnet-5",
+    ):
+        ref = get_pricing_entry(bare, provider="bedrock", base_url=url)
+        assert ref is not None, bare
+        assert ref.input_cost_per_million is not None, bare
+        assert ref.output_cost_per_million is not None, bare
+        # Output costs more than input across the Claude line; sanity-check the
+        # row isn't malformed (input < output).
+        assert ref.output_cost_per_million > ref.input_cost_per_million, bare
+        # Cache fields present so cached sessions price correctly (the #50295
+        # symptom was unknown cost on cached Bedrock Claude sessions).
+        assert ref.cache_read_cost_per_million is not None, bare
+        assert ref.cache_write_cost_per_million is not None, bare
+        # Cross-region inference profiles resolve to the same entry.
+        for mid in (f"us.{bare}", f"global.{bare}"):
+            entry = get_pricing_entry(mid, provider="bedrock", base_url=url)
+            assert entry is not None, mid
+            assert entry.input_cost_per_million == ref.input_cost_per_million, mid
+            assert entry.output_cost_per_million == ref.output_cost_per_million, mid
+
+
 def test_bedrock_cross_region_profile_prefix_resolves_to_pricing():
     """Cross-region inference profiles (us./global./eu. prefixes) must resolve
     to the same pricing entry as the bare foundation-model id.  Without prefix