Fix remaining critical, high, and medium issues from 4-perspective review

Critical fixes:
- Fix rating clamp range 1-10 → 1-5 (actual scale)
- Add `ietf ideas convergence` command (SequenceMatcher at 0.75 threshold)
- Fix "628 cross-org ideas" → 130 (verified from current DB) across 8 files

Security fixes:
- Sanitize FTS5 query input (strip special chars + boolean operators)
- Add rate limiting (10 req/min/IP) on Claude-calling endpoints
- Change <path:name> → <string:name> on draft routes

Codebase fixes:
- Add Database context manager (__enter__/__exit__)
- Wire false_positive filtering into queries (exclude by default in web UI)
- Fix Post 3 arithmetic ("~300" → "~409" distinct proposals)

Content & licensing:
- Add MIT LICENSE file
- Add IPR/FRAND notes (BCP 79, RFC 8179) to Posts 03 and 07
- Qualify "4:1 safety ratio" with monthly variation in 6 remaining files
- Add "Data as of March 2026" freeze-date headers to all 10 blog posts
- Hedge causal language in Post 04

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

data/reports/blog-series/03-oauth-wars.md

@@ -2,6 +2,8 @@
 
 *14 competing proposals, 155 protocols with no interop layer, and 25+ near-duplicate drafts. Inside the IETF's AI agent fragmentation problem.*
 
+*Analysis based on IETF Datatracker data collected through March 2026. Counts and statistics reflect this snapshot.*
+
 ---
 
 Fourteen separate Internet-Drafts are trying to solve the same problem: how should AI agents authenticate and get authorized using OAuth? They are not collaborating. They are not compatible. And they are all submitted in the same nine-month window.
@@ -131,6 +133,8 @@ The costs of this fragmentation are not theoretical:
 
 **For the ecosystem**: Each month that fragmentation persists, real-world agent deployments make choices. Those choices entrench specific approaches, making convergence harder and interoperability more expensive. The window for a unified standard narrows with every proprietary deployment.
 
+**A note on IETF IPR policy**: Implementers considering building on any of the OAuth or protocol drafts discussed above should be aware that Internet-Drafts may be subject to intellectual property rights (IPR) claims. Under BCP 79 (RFC 8179), IETF participants are expected to disclose known IPR. Check the [IETF IPR disclosure database](https://datatracker.ietf.org/ipr/) before implementing.
+
 ## The Convergence Signals
 
 Not everything is divergence. A few positive patterns emerged from the data:
@@ -157,7 +161,7 @@ Three structural interventions would accelerate convergence:
 
 - **14 competing OAuth-for-agents proposals** illustrate the depth of fragmentation; none handle chained delegation across agent networks
 - **155 A2A protocol drafts** exist without an interoperability layer; the most common idea in the corpus appears in 8 separate drafts from different teams
-- **25+ near-duplicate pairs** (>0.98 similarity) inflate the draft count; after de-duplication, roughly 300 distinct proposals remain
+- **25+ near-duplicate pairs** (>0.98 similarity) inflate the draft count; after de-duplication, roughly 409 distinct proposals remain
 - **Convergence signals exist** in EDHOC authentication, SCIM agent extensions, and verifiable conversations -- areas where teams explicitly build on each other
 - **Fragmentation goes deeper than protocols**: Chinese and Western blocs build on different RFC foundations (YANG/NETCONF vs COSE/CBOR/CoAP); the only shared bedrock is OAuth 2.0
 - **The missing piece** is a cross-protocol translation layer; no draft in the corpus addresses how agents using different protocols can interoperate