docs: Renumber duplicate ADRs to eliminate conflicts

Resolved all duplicate ADR numbers by renumbering based on chronological order:

ADR Renumbering Map:
- ADR-006-indieauth-client-identification.md → ADR-023
- ADR-010-static-identity-page.md → ADR-024
- ADR-019-indieauth-pkce-authentication.md → ADR-025
- ADR-022-indieauth-token-exchange-compliance.md → ADR-026
- ADR-022-indieauth-authentication-endpoint-correction.md → ADR-027

Files Kept Original Numbers (earliest chronologically):
- ADR-006-python-virtual-environment-uv.md (2025-11-18 19:21:31)
- ADR-010-authentication-module-design.md (2025-11-18 20:35:36)
- ADR-019-indieauth-correct-implementation.md (2025-11-19 15:43:38)
- ADR-022-auth-route-prefix-fix.md (2025-11-22 18:22:08)

Updated:
- ADR titles inside each renamed file
- Cross-references in implementation reports
- CHANGELOG.md references to ADR-025
- Renamed associated report files to match new ADR numbers

docs/decisions/ADR-023-indieauth-client-identification.md

@@ -1,4 +1,4 @@
-# ADR-006: IndieAuth Client Identification Strategy
+# ADR-023: IndieAuth Client Identification Strategy
 
 ## Status
 Accepted

docs/decisions/ADR-024-static-identity-page.md

@@ -1,4 +1,4 @@
-# ADR-010: Static HTML Identity Pages for IndieAuth
+# ADR-024: Static HTML Identity Pages for IndieAuth
 
 ## Status
 Accepted

docs/decisions/ADR-025-indieauth-pkce-authentication.md

@@ -1,4 +1,4 @@
-# ADR-019: IndieAuth Correct Implementation Based on IndieLogin.com API
+# ADR-025: IndieAuth Correct Implementation Based on IndieLogin.com API
 
 ## Status
 

docs/decisions/ADR-026-indieauth-token-exchange-compliance.md

@@ -1,4 +1,4 @@
-# ADR-022: IndieAuth Token Exchange Compliance
+# ADR-026: IndieAuth Token Exchange Compliance
 
 ## Status
 Accepted

docs/decisions/ADR-027-indieauth-authentication-endpoint-correction.md

@@ -1,4 +1,4 @@
-# ADR-022: IndieAuth Authentication Endpoint Correction
+# ADR-027: IndieAuth Authentication Endpoint Correction
 
 ## Status
 Accepted