daemon: background job orchestration for memory maintenance

Replace fragile cron+shell approach with `poc-memory daemon` — a single
long-running process using jobkit for worker pool, status tracking,
retry, cancellation, and resource pools.

Jobs:
  - session-watcher: detects ended Claude sessions, triggers extraction
  - scheduler: runs daily decay, consolidation, knowledge loop, digests
  - health: periodic graph metrics check
  - All Sonnet API calls serialized through a ResourcePool(1)

Status queryable via `poc-memory daemon status`, structured log via
`poc-memory daemon log`. Phase 1: shells out to existing subcommands.

Co-Authored-By: ProofOfConcept <poc@bcachefs.org>

Cargo.lock

@@ -755,6 +755,17 @@ version = "1.0.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "92ecc6618181def0457392ccd0ee51198e065e016d1d527a7ac1b6dc7c1f09d2"
 
+[[package]]
+name = "jobkit"
+version = "0.1.0"
+dependencies = [
+ "crossbeam-deque",
+ "log",
+ "profiling",
+ "serde",
+ "serde_json",
+]
+
 [[package]]
 name = "js-sys"
 version = "0.3.91"
@@ -1069,7 +1080,9 @@ dependencies = [
  "capnpc",
  "chrono",
  "faer",
+ "jobkit",
  "libc",
+ "log",
  "memmap2",
  "paste",
  "peg",
@@ -1125,6 +1138,25 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "profiling"
+version = "1.0.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3eb8486b569e12e2c32ad3e204dbaba5e4b5b216e9367044f25f1dba42341773"
+dependencies = [
+ "profiling-procmacros",
+]
+
+[[package]]
+name = "profiling-procmacros"
+version = "1.0.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "52717f9a02b6965224f95ca2a81e2e0c5c43baacd28ca057577988930b6c3d5b"
+dependencies = [
+ "quote",
+ "syn 2.0.117",
+]
+
 [[package]]
 name = "ptr_meta"
 version = "0.1.4"