Fluent v0.1.5

Fluent v0.1.5 focuses on making local autonomous work faster to operate and
safer to recover.

What changed

fluent status and fluent work-item show now read persisted incremental
metrics instead of recursively walking historical artifact trees. In the
release repository, warm status reads fell from tens of seconds to about
0.02 seconds.
Local coder executions now have durable owner, process-group, heartbeat, and
settlement records. fluent attempt cancel <work-item-id> <attempt-id> stops
only the recorded execution group and preserves the workspace for a retry.
A genuine round-cap pause can continue in the same Attempt after an explicit,
bounded approval:
```
fluent attempt extend <work-item-id> <attempt-id> --additional-write-rounds N
```
The approval binds the candidate and failed review contents.
Claude Writers use a managed project-local home, while the operator's Claude
project memory remains denied by the Writer sandbox.
Release installation and fluent update now require the matching .sha256
asset and preserve the installed binary if the checksum is missing or wrong.
Release publication now refuses dirty or unsynchronized source, reused tags,
failed acceptance gates, and missing version-specific release notes.

Run:

fluent update
fluent version

The reported version should start with fluent 0.1.5.

Historical Work Items keep their existing lifecycle state. To populate complete
storage totals for older artifacts, run either:

fluent work-item rebuild-metrics
fluent work-item rebuild-metrics <work-item-id>

The first command rebuilds every Work Item; the second limits the scan to one.
Normal status and show commands remain bounded reads.

Fargate execution is not part of the v0.1.5 readiness claim. Use the verified
local workflow for this release.