chore: version line to 1.1, comment cleanup, and mission.md request sources

[poxet]

Replaces #61, #62 and #63, which are closed in favour of this one. No library code changes — three project-level corrections, one commit each.

1. Version line 1.0 → 1.1

MAJOR_MINOR: '1.1' in build.yml. No 1.1.* tag exists, so the counter starts clean and the next master release publishes 1.1.0; the 1.0.x tags are untouched. Verified on CI: Computed version: 1.1.0 (previous: ).

The reason is the registration-semantics change in #60, more than the dependency removal. AddCache registrations no longer accumulate process-wide across service collections, so a host that called AddCache on one collection and expected the types on another silently loses that — a behavioural change with no compile error to warn anyone. In a three-or-more-call sequence, a call that doesn't mention a type now inherits the most recent value rather than the first-ever one.

The FluentAssertions removal is the weaker half of the argument: it can break a consumer who was unknowingly compiling against the transitive reference, but #56 shows consumers were fighting the dependency (NU1605 from pinning an older version), not relying on it.

This is the one change here with externally visible effect — it sets the version every consumer sees.

2. Remove multi-line comment blocks added in #60

Coding Guidelines allow single-line inline comments only, no multi-line blocks. Two of mine broke that:

• build.yml, Test with coverage — I appended two lines about the Microsoft.Testing.Platform migration to an existing one-line comment, making a three-line block. Removed; the flags are self-describing and global.json declares the runner, so it was history rather than something the file needs. The original line about skipping Integration and TimeCritical tests stays.
• AddCacheConcurrencyTests.cs — the note on MarkerType was two lines, now one. This one earns its single line: the nested-generic trick genuinely isn't readable from the code.

Not touched: build.yml has three pre-existing multi-line blocks (Compute version, Resolve build version, Push to NuGet). They predate this work, so removing them is a separate decision.

3. .claude/mission.md request sources

Two corrections to agent instructions — no build or runtime effect.

• Incoming requests used a literal c:\Users\... path while every other reference in the file already used $DOC_ROOT. A hard-coded path resolves on one machine and silently finds nothing elsewhere — indistinguishable from "nothing was pending", which is the failure mode that matters for a startup check.
• The Eplicta reference is removed. A Tharga project should not reference a consuming product's repository; external consumers file GitHub issues here, and the outbound duty is a comment on the issue rather than writing status into their files. That reference was also already broken — the file it named does not exist, at that path or anywhere in the Eplicta checkout. Replaced with a line stating the actual channel so it is not reintroduced.

Verification

Release build clean. CI-filtered suite: 467 tests, 465 passed, 2 skipped.

Note the suite contains two known timing-flaky tests, tracked as backlog items 9 and 13. Item 13 (TimeToLiveCacheTests.DropEvenIfUsed) carries no TimeCritical trait, so unlike item 9 it is not filtered out of CI and can redden this PR at random. If a run fails on that test, it is not this change.