feat: build system transition to release fork + archive hardening

Release fork infrastructure:
- REDBEAR_RELEASE=0.1.1 with offline enforcement (fetch/distclean/unfetch blocked)
- 195 BLAKE3-verified source archives in standard format
- Atomic provisioning via provision-release.sh (staging + .complete sentry)
- 5-phase improvement plan: restore format auto-detection, source tree
  validation (validate-source-trees.py), archive-map.json, REPO_BINARY fallback

Archive normalization:
- Removed 87 duplicate/unversioned archives from shared pool
- Regenerated all archives in consistent format with source/ + recipe.toml
- BLAKE3SUMS and manifest.json generated from stable tarball set

Patch management:
- verify-patches.sh: pre-sync dry-run report (OK/REVERSED/CONFLICT)
- 121 upstream-absorbed patches moved to absorbed/ directories
- 43 active patches verified clean against rebased sources
- Stress test: base updated to upstream HEAD, relibc reset and patched

Compilation fixes:
- relibc: Vec imports in redox-rt (proc.rs, lib.rs, sys.rs)
- relibc: unsafe from_raw_parts in mod.rs (2024 edition)
- fetch.rs: rev comparison handles short/full hash prefixes
- kibi recipe: corrected rev mismatch

New scripts: restore-sources.sh, provision-release.sh, verify-sources-archived.sh,
check-upstream-releases.sh, validate-source-trees.py, verify-patches.sh,
repair-archive-format.sh, generate-manifest.py

Documentation: AGENTS.md, README.md, local/AGENTS.md updated for release fork model

local/patches/base/P2-boot-logging.patch

@@ -1,20 +0,0 @@
-diff --git a/drivers/common/src/logger.rs b/drivers/common/src/logger.rs
-index 82ec2bd0..a531edd9 100644
---- a/drivers/common/src/logger.rs
-+++ b/drivers/common/src/logger.rs
-@@ -44,6 +44,7 @@ pub fn setup_logging(
-         Ok(b) => {
-             logger = logger.with_output(b.with_filter(file_level).flush_on_newline(true).build())
-         }
-+        Err(error) if error.raw_os_error() == Some(19) => {}
-         Err(error) => eprintln!("Failed to create {logfile_base}.log: {}", error),
-     }
- 
-@@ -61,6 +62,7 @@ pub fn setup_logging(
-                     .build(),
-             )
-         }
-+        Err(error) if error.raw_os_error() == Some(19) => {}
-         Err(error) => eprintln!("Failed to create {logfile_base}.ansi.log: {}", error),
-     }
-